Lid assembly for cup

Abstract

A lid assembly generally includes a shell body, a sealing member, and a nut. The shell body has a top portion and a circumferential portion. The shell body defines a water outlet and an air vent at an annular top surface thereof, and defines a through hole at a recessed surface thereof. The circumferential portion is provided at its outer surface with upper and lower flanges and connection means. The sealing member has a connection wing and a central shaft. The connection wing is provided with two pads capable of sealing the water outlet and the air vent, respectively. In use, the sealing member can be rotated forwardly to seal the water outlet and the air vent, thereby closing a cup fitted with the assembly. When drinking the beverage contained in the cup, the sealing member can be rotated reversely to uncover the water outlet and the air vent.

What is claimed is: 
     
         1 . A lid assembly, comprising:
 a shell body having a top portion and a circumferential portion that are integrally formed, the top portion having a recessed surface and an annular top surface around the recessed surface and defining a through hole which extends downwardly from the recessed surface, wherein the annular top surface defines a water outlet and an air vent at two opposite locations thereof, and a curved guide groove is defined at an inner surface of the through hole and extends about the through hole for a predetermined angle, the circumferential portion provided at its outer surface from its top to bottom with upper and lower flanges and connection means, an annular groove defined between the upper and lower flanges, the connection means adapted for connection to a cup, two opposite positioning protrusions formed at the upper flange and extend into the annular groove;   a sealing member having a connection wing and a central shaft formed at a center of the connection wing, the connection wing being configured to have a central concave section matching the recessed surface of the shell body, and two peripheral convex sections formed at two ends of the central concave section and extending over the annular top portion and the upper flange and provided with two pads capable of sealing the water outlet and the air vent of the shell body respectively, wherein a ledge is formed at each peripheral convex section and defines thereon a positioning indentation, the central shaft provided at its outer surface from its top to bottom with a stop protrusion, a waterproof seal ring, and a threaded portion, the sealing member capable of being installed on the shell body such that the central shaft is inserted through the through hole of the shell body, the ledge formed at each peripheral convex section is fitted into the annular groove of the shell body, the stop protrusion is capable of moving along the curved guide groove to have the positioning protrusions retained in the positioning indentations respectively; and   a nut provided with internal threads engaged with the threaded portion of the central shaft of the sealing member which extends out of the through hole of the shell body.   
     
     
         2 . The lid assembly of  claim 1 , wherein the upper flange is substantially elliptical in shape and has a maximum projection width at two opposite locations on a major axis thereof, and the water outlet and the air vent are on the major axis; the upper flange has a minimum projection width at a second pair of opposite locations on a minor axis thereof which is perpendicular to the major axis. 
     
     
         3 . The lid assembly of  claim 1 , wherein the upper flange of the shell body is substantially elliptical in shape and has a maximum thickness at a first pair of opposite locations on a major axis thereof, and the water outlet and the air vent are on the major axis, the upper flange has a minimum thickness at a second pair of opposite locations on a minor axis thereof which is perpendicular to the major axis; the upper flange gradually changing in thickness from the maximum thickness to the minimun thickness. 
     
     
         4 . The lid assembly of  claim 1 , wherein the curved guide groove begins at one end corresponding to the water outlet or the air vent, and extends about the through hole for about 90 degrees.