Patent Application
20080148474
Not applicable.
Not applicable.
The present invention relates to plumbing fixtures, and more particularly to the drain at the base of a shower enclosure.
Bathroom plumbing fixtures such as bath tubs, spas, whirlpools, shower stalls, shower surrounds, free standing partial or full shower enclosures, etc., are well known. Such fixtures can be installed in combination or as separate and discrete fixtures. In the case of stand alone shower enclosures, the upright walls that surround the enclosure are typically mounted onto to a generally flat base, sometimes referred to in the industry as a shower or base “receptor”. U.S. Pat. No. 3,457,568 provides an example of a prior art base receptor.
In addition to supporting the enclosure walls, the shower base receptor is also the floor of the enclosure on which a person stands during a shower. As such, the floor surface needs to be capable of bearing loads as well as flat and free of uneven surfaces that would be difficult or uncomfortable to stand on. At the same, the base receptor must have a drain to evacuate the water from the shower.
Many conventional base receptors provide for a recessed drain opening that is only covered by a small grate having openings for the water to pass through. The grate is recessed as well to be generally flush with the floor. However, the openings in the grate must be left unblocked and otherwise make it uncomfortable to stand on with bare feet, and therefore, the usable floor space in the enclosure is effectively reduced by the area of the grate where a person in the shower would avoid standing.
One approach to overcoming this problem is disclosed in U.S. Pat. No. 5,458,769. This patent describes a floor drain that can be used in a shower environment, albeit not specifically disclosed as for a base receptor, in which the drain opening is covered by a “bell” that can be mounted within the drain opening so that its generally flat, smooth top surface is flush (or near flush) with the surrounding floor. Fluid drains into the drain opening through a narrow passage extending around the periphery of the bell. The bell provides an improved and enlarged stepping area than conventional grates since one can comfortably stand on the smooth top surface of the bell without blocking drain flow through the narrow peripheral passage.
However, this type of covered drain typically significantly reduces the effective passage area through which water can drain, thereby reducing flow rate and possible causing flow back-up and standing water in the base receptor. Standing in drain water is unpleasant, and the raised water can slip over the short rim of the receptor base.
The slow drain problem is exacerbated when the water passing through the drain forms a vortex caused by the coriolis effect arising from suction through the drain. The vortex generates a whirlpool-like swirling action in the water as it passes down through the drain. The swirling action of the water passing through the drain can cause water that would otherwise be at the center of the drain to move outwardly toward the drain walls. The unoccupied space in the center of the drain thus effectively diminishes the passage area of the drain, and in further slows the flow rate.
Anti-vortex drains have been developed to break the vortex and allow water to pass through the full area of the drain. These anti-vortex drains are known in the swimming pool industry, and are used to address problems with debris clogging the drain and/or circulatory pumping system of the pool. They have also be developed to address safety concerns caused by the force of the suction of the circulatory system pulling body parts, particularly that of small children, toward or into the drain.
U.S. Pat. No. 5,341,523 discloses one prior art anti-vortex drain for a swimming pool application. The disclosed drain breaks up the vortex at the drain by using a large, flat circular cover flush-mounted within the drain opening. Water drains around the circular periphery of the cover in a more steady manner with less swirling action. The disclosed drain provides for adjustment of the opening size of the peripheral passage to allow for slight flow rate adjustment.
The disclosed drain would be too large and cumbersome for use in a shower receptor. Moreover, like other conventional covered drains, the reduction in drain passage area caused by use of the cover would slow the flow rate through the drain excessively in gravity feed drainage systems, such as shower applications, such that water would likely accumulate around the drain. Thus, the drain disclosed in the '423 patent, even though it is able to reduce or eliminate the vortexes and allow for passage area adjustment, would likely be suitable only for large volume applications, such as pools, which have forced flow circulatory systems and do not need to prevent water from accumulating around the drain.
Hence, a need exists to provide a shower base receptor with a covered drain system that has enhanced flow characteristics.
The invention provides a base and drain assembly for a shower enclosure. Specifically, the base has a receptor for mounting at least one upright wall of the shower enclosure. The receptor base also has a floor, a drain well and a drain opening. The drain well is recessed into the floor at the drain opening and defines a drain well perimeter extending about the drain opening. A drain cover is mounted within the drain well above the drain opening in essentially flush relation with adjacent areas of the floor. The drain cover has a drain cover perimeter spaced from the drain well perimeter so as to define a peripheral passage therebetween for peripheral flow to the drain opening beneath the drain cover. The drain cover has one or more anti-vortex ribs extending along an underside of the drain cover and toward the drain opening proximate the drain opening so as to disrupt a vortex in the water passing through the drain opening.
A preferred radially converging array lays out the ribs in angular spaced apart relation extend in radial directions such that a centerline of each rib intersects a vertical central axis of the drain cover. The ribs can be radially spaced from and symmetric about the central axis, such as in an even number of ribs, for example four, opposed to each other on opposite sides of the central axis. At least one anti-vortex rib extends to a prescribed height above the drain opening, preferably less than 0.25 inches, and more preferably between 0.10 and 0.15 inches, such as 0.13 inches. Further, one or more of the anti-vortex ribs can be contoured to follow a contour of at least one of the drain well and the drain opening. The ribs are preferably formed as a unitary part of the drain cover extending downwardly along the underside thereof.
The drain cover has an essentially planar upper surface. The drain cover perimeter is defined by at least four sides. One or more of the sides can be straight and/or one or more of the sides can be curved. In any case, the peripheral passage for drain flow can be made to be of an essentially constant dimension about the drain cover. The drain cover can have one or more edge spacers, such as one at each corner, for maintaining the horizontal dimension of the peripheral passage. The drain cover can also have one or more stand offs, again such as one each corner, for contacting the drain well and achieving a vertical gap between the drain well and other portions of the drain cover. Furthermore, the drain cover can be adapted for removable attachment to the base receptor, such as having one or more suction cups for attaching to the surface of the drain well.
Thus, the shower base receptor and drain assembly of the present invention provides a covered drain system with enhanced flow characteristics, particularly increased flow rate through the drain when compared to an uncovered drain of the same opening dimension.
Other advantages of the invention will be apparent from the detailed description which follows and accompanying drawings. What follows is merely a description of a preferred embodiment of the present invention. To assess the full scope of the invention the claims should be looked to as the preferred embodiment is not intended to be the only embodiment within the scope of the claims.
The accompanying
The assembly 20 includes a receptor base 26 providing a drain opening 28 and floor 30 of the shower enclosure 22. The upright walls 24 are supported by the receptor base 24 along the peripheral edges and adjacent the rear and side flanges 32. The floor 30 is a dished bottom surface that slopes toward the drain opening 28 located in a recessed drain well 34 at its center. The drain well 34 has a generally vertical edge walls 36 defining the drain well periphery 38.
The drain well 34 removably receives a drain cover 40 as shown in
The underside of the drain cover 40 has several elements formed integrally with the top surface 42. Four receptors 60 are formed at the four corners of the drain cover 40 for support elastomeric stand-offs 62 providing contact surfaces resting against both the recessed floor within the drain well 34 as well as the peripheral edge walls defining the drain well periphery 38. The stand-offs 62 thus provide firm, yet slightly cushioned contact areas for the drain cover 40 to seat inside the drain well 34 centered within the drain well periphery 38. Of course, the stand-offs 62 could be formed of the same material as the rest of the drain cover 40, however, using a co-molding process the elastomeric material can be used to permit flexibility along a controlled range of vertical and lateral movement of the drain cover 40 within the drain well 42 when a load is applied to the drain cover 40. Six small cylindrical “buttons” 64 with co-molded elastomeric material are also formed at the underside of the drain cover 40 to provide for cushioned structural support against vertical loading.
For example, under wet conditions, a 70 lb-f load and with the stand-off spaced 0.63 inches from the drain cover periphery, the drain cover 40 could be permitted to move at the short sides 44 laterally (horizontally) 0.011 inches and vertically 0.007 inches, at the long sides 0.04 inches laterally and 0.005 inches vertically, and at the and corners 0.19 inches at the corners, and 0.008 inches vertically. Moreover, it is further noted that each of the stand-offs 62 could be formed in two parts, one for supporting vertical loads and one for centering the drain cover 40 in the drain well 34. It should be noted that while these values are provide for a 70 lb-f load, the drain cover 40 is preferably rated for 300 lb-f loads, as is commonly required by code for grates.
Furthermore, the underside of the drain cover 40 has two receptors 66 near the midpoint of the long sides 46 for receiving suction cups 70. The suction cups 70 removably attach to the floor within the drain well 34 and apply a releasable vertical (and lateral) suction force tending to keep the drain cover 40 mounted within the drain well 34.
By centering the drain cover 40 within the drain well 34 and limiting the movement therein, the stand-offs 62 serve to maintain a peripheral passage 78 extending about the drain cover 40 at the spacing between the drain cover periphery 50 and the drain well periphery 38. In the preferred embodiment described herein, the peripheral passage 78 is of an essentially constant gap width “W” (see
As best shown in
The four anti-vortex ribs 90 are arranged in a radially converging pattern as well. In the orientation of the drain cover 40 as shown in
The arrangement and quantity of anti-vortex (and structural) ribs can vary. However, the radial array arrangement allows the ribs to channel water toward the center of the drain opening 28 from all sides of the drain cover 40 along the entire drain cover periphery 50. While other arrangements could be used, those that act as baffles or others impede flow to the drain opening 28 should be avoided so as not to slow the flow rate.
The number of anti-vortex ribs in the preferred embodiment described herein was selected to be four after empirical evidence determined an increased flow rate when compared to both no anti-vortex ribs and eight anti-vortex ribs. For example, it was determined that, holding other parameters constant, four ribs provided an 11% improvement in flow rate when compared to eight ribs.
All of the ribs 80 and 90 depend transversely (vertically) from the underside of the drain cover 40, and can be parallel to the center axis 92. The structural ribs 80 are sized to meet the loading requirements of a covered shower drain, for example 300 lb-f. The shape and transverse dimension of the anti-vortex ribs 90 are selected to prevent, eliminate, disrupt or otherwise break up any vortex that would otherwise be present in the drain.
As can be seen in
The prescribed height H, that is the distance from the bottom of the anti-vortex ribs 90 and a top plane of the drain opening 28, significantly effects the break up of the vortex, and in turn the flow rate through the drain. The prescribed height “H” (see
It was found that the presence of the drain cover 40 using anti-vortex ribs 90 to eliminate the vortex at the drain opening 28 actually increases the flow rate through the drain opening 28 over that when no drain cover 40 was used at all. Empirical study has shown that in a particular gravity fed shower drain application in which a conventional drain grate 100, as shown in
While there has been shown and described what is at present considered a preferred embodiment of the invention, various changes and modifications can be made therein without departing from the scope of the invention defined by the appended claims. Therefore, various alternatives and revised embodiments are contemplated as being within the scope of the following claims.
The invention provides a base for a shower enclosure having a flat stepping area at a covered drain with peripheral flow and anti-vortex features that enhance the flow rate of water through the drain.
