1. Field of the Invention
The present invention relates generally to plumbing fixtures. In particular, the invention relates to an overflow drain in a container.
2. Description of Related Art
The inner volume of a bathtub or sink is defined by a plurality of vertical walls. One of these walls includes can include an overflow drain opening formed therein. When water is added to the bathtub, the overflow drain prevents the bathtub from overflowing by providing an outlet for water at a level near the top of the bathtub. Conventionally, the overflow drain is a pipe having a known diameter to enable contents to flow out of the bathtub or sink at least as fast as a predetermined rate.
A cover or escutcheon is used to conceal the overflow drain for at least aesthetic purposes. The plate covers all or part of the overflow drain and may have holes therein to permit water to enter without completely sealing the overflow drain. These plates or escutcheons typically are designed to cover overflow drains virtually in their entirety, but include an opening in a lower portion. The opening enables water to exit the bathtub and enter the overflow drain.
When a person enters a partially filled bathtub or items are put in partially filled sink, water is displaced and the water level rises. This displacement can cause the water to rise to a level higher than the overflow drain. When this occurs, water channels through the plate opening and exits the tub through the overflow drain. The water level is thereby maintained at a maximum level that is no higher than the lowest portion of the overflow drain. That is, the vertical location of the bottom of the overflow drain along the vertical wall of the tub, therefore, determines the maximum height of the water level in the bathtub.
In one aspect of the invention, an overflow drain cover assembly includes a weir having a cavity portion. When mounted to an overflow drain on a substantially vertical wall of a container, the cavity portion forms a first gap at a top of the weir. The weir blocks contents of the container below the top of the weir from entering the overflow drain. A first cross-sectional area of the first gap is a minimum of 1000 square millimeters.
In another feature, the overflow drain cover assembly has a gasket between the weir and the vertical wall, the gasket enhancing a seal between the weir and the vertical wall when the weir is mounted to the overflow drain. A cover covering the weir and having one or more openings on a bottom surface allows contents of the container to enter the cavity portion behind the cover, the cover forming a second gap between the weir and the cover. A total cross-sectional area of the one or more openings, a second cross-sectional area of the second gap, and the first cross-sectional area of the first gap are substantially equal.
In another feature, the first cross-sectional area of the first gap is a maximum of 1500 square millimeters.
The present invention is an overflow drain cover assembly for covering all or part of an overflow drain in a container. The overflow drain in a container limits the level to which the contents of the container may rise by providing a controlled outlet for the contents when the contents rise above the lowermost point of the drain. In this manner, the overflow drain can avoid having the contents of the container from overflowing the edges of the container in an uncontrolled manner. The overflow drain cover assembly according to the present disclosure can raise the level to which the contents of the container may rise before draining through the overflow drain and maintain the function of avoiding the contents from overflowing the edges of the container.
A cover 514, shown in cutaway view, covers the weir creating a second gap 522 therebetween. A cross-section area of the second gap is represented by the cross-hatched area 524. In one embodiment, the cross-sectional area 524 of the first gap is a minimum of 1000 square millimeters and preferably a maximum of 1500 square millimeters.
Thus, the overflow drain cover assembly raises the level of water in the tub from the bottom of the overflow drain to the top of the weir. This allows for more water in the bathtub and deeper water for the user. The top of the weir is above the bottom of the overflow drain and has the opening gap at the top of the weir. This allows the waterline in the tub to fill to a higher level before it spills over weir into the overflow drain. The water enters the bottom of the overflow cover through the openings in the bottom of the cover and fills up the inside of the overflow assembly until it reaches the top of the weir. The openings in the bottom of the cover allow water to enter and flow up and into the overflow hole. The sealing gasket on the back side of the weir prevents water from entering the overflow drain until the water has reached the top of the weir. With this overflow drain cover assembly installed, the user can fill the bathtub to a higher level and experience a deeper immersion of the user's body in an existing bathtub shape.
In an embodiment, the cross sectional area of the cover opening at the bottom of the cover, the cross sectional area of the second gap between the cover and the weir and the cross sectional area of the first gap between the top of the weir and the overflow drain are the same. The larger the cross-sectional area of these three sections, the larger the volume of water flowing into the overflow drain. The upper limit of that flow rate area is reached when the cross sectional area of any of the three opening is equal to the cross sectional area of the overflow drain pipe diameter.
Other embodiments of the present invention are within the scope of the following claims.