WO2008156307A2

WO2008156307A2 - Lid assembly and garbage can using the same

Info

Publication number: WO2008156307A2
Application number: PCT/KR2008/003464
Authority: WO
Inventors: Kyoung-Soo Choi; Jang-Won Lee
Original assignee: Nuriinternational Co., Ltd.
Priority date: 2007-06-18
Filing date: 2008-06-18
Publication date: 2008-12-24
Also published as: WO2008156307A3

Abstract

A lid assembly for use in a garbage can includes a cap having an inlet opening through which an object can be put. The lid assembly further includes a lid having an upper surface, a first end fixed to the cap through a hinge and a second end kept free. The lid is installed in the inlet opening of the cap in such a manner that the lid can be rotated about the hinge to open and close the inlet opening. The upper surface of the lid is brought into contact with an edge of the inlet opening of the cap in a non-loaded balanced state to close the inlet opening. The lid is rotated about the hinge by the weight of the object to open the inlet opening when the object is placed on the upper surface of the lid.

Description

Description LID ASSEMBLY AND GARBAGE CAN USING THE SAME

Technical Field

[1] The present invention relates to a lid assembly and a garbage can using the same, and, more particularly, to a lid assembly which allows a lid to be smoothly opened by the weight of an object placed thereon, such as a waste, so that the object can be easily introduced into a container body, and a garbage can using the same. Background Art

[2] In general, the wastes produced through a daily life are temporarily received in a garbage can provided in a room. When a specified amount of wastes is collected in the garbage can, the wastes are transferred to a garbage bag and are disposed. A typical garbage can is disclosed in Korean Utility Model Publication No. 20-0267115B. The garbage can disclosed in this document includes a container body which has an open end for receiving wastes, a cap which is coupled to the open end of the container body and has an inlet opening, and a lid which is rotatable about hinges to open and close the inlet opening of the cap. In order to dump wastes, it is necessary for a user to directly push the lid into an open position and then put the wastes into the container body through the inlet opening of the cap. However, the outer surface of the lid is likely to be contaminated by foreign materials which may be transferred to the user's hands, thereby posing a sanitary problem.

[3] U.S. Patent Nos. 6,857,538 and 7,225,943 disclose garbage cans in which the cover of a garbage can is opened by pressing a pedal with the foot of a user for sanitary purposes. However, the technique disclosed in these Patent documents has a problem in that the cover can be opened only when the user presses the pedal using his or her foot, thereby causing cumbersomeness and inconvenience to the user. Moreover, since the pedal installed in the lower part of a container body and the cover installed in the upper part of the container body are connected with each other by a link member, the garbage cans are complicated in structure, costly to produce and highly vulnerable to troubles. Disclosure of Invention

Technical Problem

[4] Accordingly, the present invention has been made in an effort to solve the problems inherent in the prior art, and an object of the present invention is to provide a lid assembly which allows a lid to be opened by the weight of an object placed thereon, such as a waste, so that the object can be conveniently and sanitarily introduced into a container body, and a garbage can using the same. [5] Another object of the present invention is to provide a lid assembly in which the center of gravity of a lid can be conveniently adjusted depending upon the weight of an object placed thereon, so that the object can be easily introduced into a container body, and a garbage can using the same.

[6] A further object of the present invention is to provide a lid assembly that allows a garbage bag to be readily capped inside a container body, and a garbage can using the same.

[7] A still further object of the present invention is to provide a lid assembly that allows a garbage bag to be capped inside a container body with the mouth end thereof opened widest, and a garbage can using the same. Technical Solution

[8] In accordance with one aspect of the present invention, there is provided a garbage can comprising: a garbage can body having an open upper end; a cap detachably coupled to the open upper end of the garbage can body and having an inlet opening through which a waste can be put into the garbage can body; and a lid having an upper surface, a first end fixed to the cap through a hinge and a second end kept free, the lid installed in the inlet opening of the cap in such a manner that the lid can be rotated about the hinge to open and close the inlet opening, the upper surface of the lid being brought into contact with an edge of the inlet opening of the cap in a non-loaded balanced state to close the inlet opening, the lid being rotated about the hinge by the weight of the waste to open the inlet opening when the waste is placed on the upper surface of the lid.

[9] In accordance with another aspect of the present invention, there is provided a lid assembly comprising: a cap having an inlet opening through which an object can be put; and a lid having an upper surface, a first end fixed to the cap through a hinge and a second end kept free, the lid installed in the inlet opening of the cap in such a manner that the lid can be rotated about the hinge to open and close the inlet opening, the upper surface of the lid being brought into contact with an edge of the inlet opening of the cap in a non-loaded balanced state to close the inlet opening, the lid being rotated about the hinge by the weight of the object to open the inlet opening when the object is placed on the upper surface of the lid.

[10] The above objects, and other features and advantages of the present invention will become more apparent after a reading of the following detailed description taken in conjunction with the drawings. Brief Description of the Drawings

[11] Fig. 1 is a perspective view illustrating the construction of a garbage can to which a lid assembly in accordance with a first embodiment of the present invention is applied; [12] Fig. 2 is an exploded perspective view illustrating the garbage can shown in FIG. 1;

[13] Fig. 3 is a sectional view illustrating the garbage can shown in Fig. 1;

[14] Fig. 4 is a partially sectional view illustrating a lid and a balance weight used in the garbage can shown in Fig. 1 ;

[15] Figs. 5 through 7 are sectional views for explaining how the lid of the garbage can shown in Fig. 1 is opened and closed by the weight of a waste;

[16] Fig. 8 is a perspective view illustrating the construction of a garbage can to which a lid assembly in accordance with a second embodiment of the present invention is applied;

[17] Fig. 9 is an exploded perspective view illustrating the garbage can shown in FIG. 8;

[18] Fig. 10 is a sectional view illustrating the garbage can shown in Fig. 8;

[19] Fig. 11 is a sectional view for explaining how a lid of the garbage can shown in Fig.

8 is opened and closed by the weight of a waste;

[20] Fig. 12 is a sectional view illustrating the construction of a garbage can to which a lid assembly in accordance with a third embodiment of the present invention is applied; and

[21] Fig. 13 is a sectional view for explaining how a lid of the garbage can shown in Fig.

12 is opened and closed by the weight of a waste. Best Mode for Carrying Out the Invention

[22] Preferred embodiments of a lid assembly and a garbage can using the same in accordance with the present invention will now be described in detail with reference to the accompanying drawings.

[23] Illustrated in Figs. 1 through 7 is a garbage can to which a lid assembly in accordance with a first embodiment of the present invention is applied. Referring to Figs. 1 and 2, the garbage can includes a garbage can body 10 for receiving various wastes 2 and a lid assembly of a first embodiment. The lid assembly includes a cap 20, a lid 50, and a gravity center adjustment means 60. It is to be noted that the lid assembly according to the present embodiment can be applied not only to the garbage can but also to various kinds of containers for receiving different objects.

[24] Referring to Figs. 1 through 3, an open end 12 for introducing a waste 2 is formed at the upper end of the garbage can body 10. An engagement shoulder 14 is formed on the inner surface of and adjacent to the upper end of the garbage can body 10 to extend in the circumferential direction. While the garbage can body 10 shown in Figs. 1 and 2 has a cylindrical configuration, this shall be understood as illustrative and not in a limiting sense. Alternatively, the garbage can body 10 may be formed into various other configurations and structures suitable for receiving wastes, such as a quadrangle, an oval or the like. [25] The cap 20 is detachably coupled to the open upper end 12 of the garbage can body

10. The cap 20 is composed of an outer tube 30 and an inner tube 40. The outer tube 30 has a hole 32 which communicates with the open upper end 12 of the garbage can body 10. A skirt 34 extends from the lower end of the outer tube 30. The skirt 34 is coupled to the open upper end 12 of the garbage can body 10. The inner tube 40 is coupled in the outer tube 30 and has an inlet opening 42 which communicates with the open upper end 12 of the garbage can body 10. The inlet opening 42 of the inner tube 40 is defined obliquely. The outer tube 30 and the inner tube 40 are formed to have a hopper- like sectional shape so that the sectional area thereof is gradually decreased in the downward direction.

[26] The outer tube 30 and the inner tube 40 can be formed by injection-molding a plastic material. While the outer tube 30 and the inner tube 40 are independently formed in the present embodiment, it is to be appreciated that they may be integrally formed with each other.

[27] Referring to Figs. 2 through 4, the lid 50 is installed such that it can be rotated about hinges 52 to open and close the inlet opening 42 of the inner tube 40. The upper surface of the lid 50 is configured such that it can make close contact with the edge of the inner tube 40 in a non-loaded balanced state to close the inlet opening 42. The lid 50 has one end 54a and the other end 54b. One end 54a of the lid 50 is adjacent to the hinges 52, and the other end 54b of the lid 50 serves as a free end which is distant from the hinges 52. The lid 50 is installed to be tilted downwards from one end 54a to the other end 54b. Each hinge 52 is composed of a hinge shaft 52a which is formed on the lower end portion of the inner tube 40 adjacent to the inlet opening 42 and a hinge hole 52b which is defined adjacent to one end 54a of the lid 50 to allow the hinge shaft 52a to be fitted therein. A bearing 52c is inserted in the hinge hole 52b such that the hinge shaft 52a can be rotated smoothly.

[28] An extension plate portion 56 is bent downwards from one end 54a of the lid 50. A plurality of threaded holes 58a through 58c is defined in the extension plate portion 56 and arranged in the vertical direction. While three threaded holes 58a through 58c are defined in the extension plate portion 56 in the present embodiment, the number of the threaded holes can be arbitrarily changed as the occasion demands. A packing may be attached to the edge 42 of the lid 50 to ensure air-tightness, thereby preventing leakage of an offensive odor from the garbage can body 10.

[29] The gravity center adjustment means 60, which is disposed between one end 54a and the other end 54b of the lid 50 to adjust the center of gravity of the lid 50, includes a balance weight 62. A threaded rod 64 is integrally formed with one end of the balance weight 62. The threaded rod 64 of the balance weight 62 is selectively locked to any one of the threaded holes 58a through 58c of the extension plate portion 56 to adjust the center of gravity of the lid 50. The upper surface of the lid 50 is rotated about the hinges 52 by the weight of the balance weight 62 and is brought into close contact with the edge of the inlet opening 52 in the non-loaded balanced state. As a user unlocks the threaded rod 64 and changes the locking position of the balance weight 62, the center of gravity of the lid 50 is adjusted. In the meantime, a balance weight for adjusting the center of gravity of the lid 50 can be fixedly secured to one surface of the extension plate portion 56.

[30] Referring to Figs. 2 and 3, a garbage bag 4 can be additionally provided in the garbage can body 10 so that the waste 2 can be received in the garbage bag 4. The garbage bag 4 has an upper mouth end 6 having a size great enough to cover the open upper end 12 of the garbage can body 10. The garbage bag 4 may be made of vinyl. A ring 70 is removably engaged with the engagement shoulder 14 of the garbage can body 10 to fix the upper mouth end 6 of the garbage bag 4 to the inner surface of the open upper end 12 of the garbage can body 10.

[31] Hereinafter, the operation of the lid assembly and the garbage can using the same will be described in detail.

[32] Referring to Figs. 2 and 3, the garbage bag 4 for receiving the waste 2 is capped inside the garbage can body 10 so that the waste 2 can be sanitarily received and disposed. To this end, the user decouples the garbage can body 10 and the outer tube 30 from each other and removes the ring 70 which is engaged with the engagement shoulder 14 of the garbage can body 10. Then, with the upper mouth end 6 of the garbage bag 4 is open wide, the ring 70 is surrounded by the upper edge of the garbage bag 4. Next, by engaging the ring 70 with the engagement shoulder 14, the garbage bag 4 is fixedly held between the garbage can body 10 and the ring 70. Since the upper edge of the garbage bag 4 surrounds the ring 70, the upper mouth end 6 of the garbage bag 4 can be kept in a circular sectional shape. Therefore, the edge of the garbage bag 4 adjacent to the open upper end 12 of the garbage can body 10 is prevented from being partially deformed and projecting into the garbage can body 10. This eliminates the possibility that the inlet opening 42 is partially closed and the open upper end 12 becomes narrow, which would otherwise impede introduction of the waste 2 and hinder the opening and closing operation of the lid 50.

[33] As the user fits the skirt 34 of the outer tube 30 into the open upper end 12 of the garbage can body 10, the assembly of the garbage can body 10 and the cap 20 is completed, so that the garbage bag 4 can be reliably capped inside the garbage can body 10. If the garbage bag 4 is full of the wastes 2, the user decouples the garbage can body 10 and the outer tube 30 from each other. After the user removes the ring 70 and the garbage bag 4 from the inside of the garbage can body 10, the garbage bag 4 is disposed by detaching the garbage bag 4 from and the ring 70. [34] Referring to Figs. 5 and 6, as the user crumples a tissue paper sheet and throws it into the inner tube 40, the tissue paper sheet, i.e., the waste 2, thrown into the hopper-like inner tube 40 is naturally guided onto the lid 50. At this time, the lid 50 is rotated about the hinges 52 by the weight of the waste 2 and is opened consequently. The lid 50 is tilted such that one end 54a thereof adjacent to the hinges 52 is positioned higher than the other end 54b thereof. The waste 2 guided onto the lid 50 slips downwards along the upper surface of the lid 50 toward the other end 54b. If the waste 2 approaches the other end 54b of the lid 50, the moment applied to the other end 54b by the weight of the waste 2 is increased, as a result of which the lid 50 is smoothly rotated about the hinges 52.

[35] As shown in Fig. 7, as the lid 50 is opened, the waste 2 passes through the inlet opening 42 of the inner tube 40 and is received in the garbage bag 4 capped inside the garbage can body 10. After the waste 2 is received in the garbage can body 10, the opened lid 50 is rotated again about the hinges 52 and is returned back to its original position where it is kept in the balanced state. The upper surface of the lid 50 makes contact with the edge of the inlet opening 42 to ensure airtightness. Accordingly, it is possible to prevent an offensive odor of the waste 2 from leaking out of the garbage can body 10.

[36] Referring to Figs. 2 through 4, when the garbage can according to the present invention is in use, the user can adjust the center of gravity of the lid 50 so that the lid 50 can be smoothly opened even by a lightweight waste 2. To this end, the user decouples the inner tube 40 from the outer tube 30. With the inner tube 40 turned upside down, the threaded rod 64 of the balance weight 62, which is locked into any one of the threaded holes 58a through 58c of the extension plate portion 56, is loosened or tightened. As the balance weight 62 approaches one end 54a of the lid 50, the center of gravity of the lid 50 moves toward the other end 54b of the lid 50. As the balance weight 62 goes away from one end 54a of the lid 50, the center of gravity of the lid 50 moves toward one end 54a of the lid 50.

[37] As best shown in Fig. 4, the moment applied to the lid 50 by the weight of the balance weight 62 when the threaded rod 64 of the balance weight 62 is locked to the third lowermost threaded hole 58c is greater than the moment acting when the threaded rod 64 of the balance weight 62 is locked to the first uppermost threaded hole 58a. That is to say, when the balance weight 62 is locked into the first threaded hole 58a, the smallest moment is applied to the lid 50, and when the balance weight 62 is locked into the third threaded hole 58c, the greatest moment is applied to the lid 50. If the balance weight 62 is locked into the second threaded hole 58b lying between the first and third threaded holes 58a and 58c, an intermediate level of moment is applied to the lid 50. Accordingly, the user can easily control the opening and closing operation of the lid 50 caused by the weight of the waste 2 by adjusting the locking position of the balance weight 62.

[38] Figs. 8 through 11 illustrate a garbage can to which a lid assembly in accordance with a second embodiment of the present invention is applied. Referring to Figs. 8 through 10, the garbage can includes a garbage can body 110 for receiving various kinds of wastes 2 and a lid assembly. The lid assembly includes a cap 120, a lid 150, and a gravity center adjustment means 160. Similar to the lid assembly according to the first embodiment, the lid assembly of the present embodiment can be applied not only to the garbage can but also to various kinds of containers for receiving different objects.

[39] An open end 112 for introducing a waste 2 is formed at the upper end of the garbage can body 110. The cap 120 is detachably coupled to the open upper end 112 of the garbage can body 110. The cap 120 has an inlet opening 122 which communicates with the open upper end 112 of the garbage can body 110. The cap 120 is formed to have a hopper-like sectional shape so that the sectional area thereof can be gradually decreased in the downward direction. A packing 124 is secured to the lower surface of the cap 120 around the inlet opening 122.

[40] The lid 150 is horizontally installed to open and close the inlet opening 122 of the cap 120 when rotated about hinges 152. The upper surface of the lid 150 makes close contact with the packing 124 in a non-loaded balanced state so as to airtightly close the inlet opening 122 to thereby prevent leakage of an offensive odor. The lid 150 has one end 154a and the other end 154b. One end 154a of the lid 150 is adjacent to the hinges 152, and the other end 154b of the lid 150 serves as a free end which is distant from the hinges 152. Each hinge 152 is composed of a hinge shaft 152a which is formed in the lower end portion of the cap 120 adjacent to the inlet opening 122 and a hinge hole 152b which is defined adjacent to one end 154a of the lid 150 to allow the hinge shaft 152a to be fitted therein.

[41] An extension plate portion 156 is bent downwards from one end 154a of the lid 150.

The extension plate portion 156 does not make contact with the edge of the inlet opening 122 until the lid 150 completely opens the inlet opening 122. A threaded hole 158 is defined at the distal end of the extension plate portion 156. While the inlet opening 122 and the lid 150 illustrated in Figs. 8 and 9 have a circular sectional shape, this shall be understood as illustrative and not in a limiting sense. Alternatively, the sectional shape of the inlet opening 122 and the lid 150 may be changed as desired.

[42] As shown in Figs. 9 and 10, the gravity center adjustment means 160 includes a screw 162 which is locked into the threaded hole 158 of the extension plate portion 156. The lid 150 is rotated about the hinges 152 by the weight of the screw 162 and is brought into close contact with the edge of the inlet opening 122 in a non-loaded balanced state. While one screw 162 is locked to the distal end of the extension plate portion 156 in the illustrated embodiment, the number and the position of screws may be arbitrarily changed. The gravity center adjustment means 160 further includes a balance weight 164 which is secured to one surface of the extension plate portion 156 to maintain the lid 150 in a balanced state on the hinges 152. In the present embodiment, it is possible to omit the screw 162. In this case, only the balance weight 164 is secured to one surface of the extension plate portion 156 to adjust the center of gravity of the lid 150.

[43] If the screw 162 is tightened, the center of gravity of the lid 150 moves toward the other end 154b of the lid 150. If the screw 162 is loosened, the center of gravity of the lid 150 moves toward one end 154a of the lid 150. If the waste 2 is lightweight, the tightening degree of the screw 162 is increased so that the lid 150 can be opened by the lightweight waste 2.

[44] Referring to Figs. 10 and 11, as the user dumps a waste 2 into the cap 120, the waste

2 is naturally guided onto the lid 150. At this time, the lid 150 is rotated about the hinges 152 by the weight of the waste 2 and is opened consequently. If the lid 150 is opened, the waste 2 passes through the open upper end 112 and is received in the garbage can body 110. After the waste 2 is received in the garbage can body 110, the opened lid 150 is rotated again about the hinges 152 and is returned back to its original position where it is kept in a balanced state. The upper surface of the lid 150 makes contact with the packing 124 to airtightly close the inlet opening 122.

[45] Figs. 12 and 13 illustrate a garbage can to which a lid assembly in accordance with a third embodiment of the present invention is applied. Referring to Figs. 12 and 13, the garbage can includes a garbage can body 210 for receiving various wastes 2 and a lid assembly. The lid assembly includes a cap 220, a lid 250, and a gravity center adjustment means 260. Since the garbage can body 210, the cap 220, the lid 250, and the gravity center adjustment means 260 of the third embodiment are the same in construction and function as the garbage can body 110, the cap 120, the lid 150, and the gravity center adjustment means 160 of the second embodiment, detailed description thereof will be omitted herein.

[46] The cap 220 is detachably coupled to an open upper end 212 of the garbage can body

210. An inlet opening 222 of the cap 220 is defined obliquely along an inclined surface 226 of the cap 220. The lid 250 is obliquely installed such that it can be rotated about hinges 252 to open and close the inlet opening 222. One end 254a of the lid 250 is adjacent to the upper end of the inlet opening 222, and the other end 254b of the lid 250 is adjacent to the lower end of the inlet opening 222. A screw 262 serving as the gravity center adjustment means 260 is locked to an extension plate portion 256 of the lid 250. A balance weight 264 is secured to one surface of the extension plate portion 256 to maintain the lid 250 in a balanced state on the hinges 252.

[47] In the garbage can constructed as above, as the user throws a waste 2 into the cap

220, the waste 2 slips along the inclined surface 226 and is guided onto the lid 250. The waste 2 placed on the lid 250 also slips along the lid 250 toward the other end 254b of the lid 250. As the waste 2 approaches the other end 254b of the lid 250, the moment applied to the lid 250 is increased, whereby the lid 250 is smoothly rotated about the hinges 252. If the lid 250 is opened, the waste 2 passes through the inlet opening 222 and the open upper end 212 and is received in the garbage can body 210. After the waste 2 is received in the garbage can body 210, the opened lid 250 is rotated again about the hinges 252 by the weights of the screw 262 and the balance weight 264 and is returned back to its original position where it is kept in a balanced state. The upper surface of the lid 250 makes contact with a packing 224 to ensure airtightness.

[48] The embodiments shown and described hereinabove should not be construed to limit the scope of protection of the present invention. The scope of the invention shall be limited only by the subject matters recited in the claims. It will be understood by those skilled in the art that various changes and modifications may be made without departing from the scope of the invention defined in the claims. Industrial Applicability

[49] As is apparent from the above description, the lid assembly and the garbage can using the same according to the present invention provide advantages in that, since a lid can be automatically opened by the weight of an object placed thereon, such as a waste, the object can be conveniently and sanitarily introduced into a container body. Also, because the center of gravity of the lid can be conveniently adjusted depending upon the weight of the object to be placed thereon, the object can be easily introduced into the container body. Moreover, a garbage bag can be conveniently capped inside the body of the container in a state that the mouth end of the garbage bag is opened widest.

Claims

[1] A garbage can comprising: a garbage can body having an open upper end; a cap detachably coupled to the open upper end of the garbage can body and having an inlet opening through which a waste can be put into the garbage can body; and a lid having an upper surface, a first end fixed to the cap through a hinge and a second end kept free, the lid installed in the inlet opening of the cap in such a manner that the lid can be rotated about the hinge to open and close the inlet opening, the upper surface of the lid being brought into contact with an edge of the inlet opening of the cap in a non-loaded balanced state to close the inlet opening, the lid being rotated about the hinge by the weight of the waste to open the inlet opening when the waste is placed on the upper surface of the lid.

[2] The garbage can according to claim 1, further comprising: a gravity center adjustment means mounted to the first end of the lid for allowing a user to adjust the center of gravity of the lid.

[3] The garbage can according to claim 2, wherein an extension plate portion is formed at the first end of the lid, a plurality of threaded holes being arranged in the extension plate portion along a vertical direction, and wherein the gravity center adjustment means comprises a balance weight having a threaded rod selectively locked to any one of the plurality of threaded holes.

[4] The garbage can according to claim 2, wherein the gravity center adjustment means comprises a threaded rod locked to the first end of the lid.

[5] The garbage can according to claim 4, wherein an extension plate portion is formed at the first end of the lid to extend downwards, the threaded rod being locked to a distal end of the extension plate portion, and wherein the gravity center adjustment means further comprises a balance weight mounted to the extension plate portion so that the lid can maintain a balance about the hinge.

[6] The garbage can according to claim 1, wherein an extension plate portion is formed at the first end of the lid and a balance weight is mounted to one surface of the extension plate portion.

[7] The garbage can according to claim 1, wherein the cap comprises: a cylindrical outer tube detachably coupled to the open upper end of the garbage can body; and an inner tube coupled inside the outer tube, the inlet opening being formed obliquely in the inner tube.

[8] The garbage can according to claim 1, wherein an engagement shoulder is forme d on an upper inner surface of the garbage can body and a ring for holding an edge of a garbage bag is engaged with the engagement shoulder.

[9] The garbage can according to claim 1, wherein the upper surface of the lid is inclined to ensure that the waste placed on the lid can slip toward the second end of the lid.

[10] The garbage can according to claim 1, wherein the inlet opening is formed to have a sectional area gradually decreasing in a downward direction, and wherein a packing is provided between the inlet opening of the cap and the lid to ensure airtightness.

[11] A lid as sembly comprising : a cap having an inlet opening through which an object can be put; and a lid having an upper surface, a first end fixed to the cap through a hinge and a second end kept free, the lid installed in the inlet opening of the cap in such a manner that the lid can be rotated about the hinge to open and close the inlet opening, the upper surface of the lid being brought into contact with an edge of the inlet opening of the cap in a non-loaded balanced state to close the inlet opening, the lid being rotated about the hinge by the weight of the object to open the inlet opening when the object is placed on the upper surface of the lid.

[12] The lid assembly according to claim 11, further comprising: a gravity center adjustment means mounted to the first end of the lid for allowing a user to adjust the center of gravity of the lid.

[13] The lid assembly according to claim 12, wherein an extension plate portion is formed at the first end of the lid, a plurality of threaded holes being arranged in the extension plate portion along a vertical direction, and wherein the gravity center adjustment means comprises a balance weight having a threaded rod selectively locked to any one of the plurality of threaded holes.

[14] The lid assembly according to claim 13, wherein the gravity center adjustment means comprises a threaded rod locked to the first end of the lid.

[15] The lid assembly according to claim 14, wherein an extension plate portion is formed at the first end of the lid to extend downwards, the threaded rod being locked to a distal end of the extension plate portion, and wherein the gravity center adjustment means further comprises a balance weight mounted to the extension plate portion so that the lid can maintain a balance about the hinge.

[16] The lid assembly according to claim 11, wherein an extension plate portion is formed at the first end of the lid and a balance weight is mounted to one surface of the extension plate portion.

[17] The lid assembly according to claim 11, wherein the cap comprises: a cylindrical outer tube; and an inner tube coupled inside the outer tube, the inlet opening being formed obliquely in the inner tube. [18] The lid assembly according to claim 11, wherein the upper surface of the lid is inclined to ensure that the object placed on the lid can slip toward the second end of the lid. [19] The lid assembly according to claim 11, wherein the inlet opening is formed to have a sectional area gradually decreasing in a downward direction, and wherein a packing is provided between the inlet opening of the cap and the lid to ensure air-tightness.