Abstract
A trap is formed from two instances of a standard part, the ninety degree elbow, and a two-part ninety degree elbow that has a cross-section that runs from circular at the upstream spigot to ovoid at the juncture of the two parts back to circular at the downstream hub. All of the rules that bind trap design in building codes can still be accommodated in this trap architecture. Moreover, the ability of the critical flattened elbow part to be formed from two plastic parts with standard line-of-draw cores reduces entry cost of fabrication. Access to the interior of the parts also allows for novel internal coating strategies. Most importantly for installation, the height of whole trap is reduced by squishing the trap diameter to a degree that a significant drop in trap height is achieved. This decrease in trap height can be sufficient to allow the trap to be accommodated in the reduced height of a vertical space between an underlying ceiling and the underside of the lowered subfloor.
Claims
1. A two-spigot ninety-degree elbow for connecting an upstream ninety-degree elbow and a downstream ninety-degree elbow, the two-spigot ninety-degree elbow comprising: a circular upstream spigot; a circular downstream spigot oriented at a ninety-degree angle relative to the circular upstream spigot; and a body portion extending from the circular upstream spigot to the circular downstream spigot, from the circular upstream spigot the body portion tapers outward to a maximum width that is wider than the circular upstream spigot and wider than the circular downstream spigot, an upper surface of the body portion tapers downward from the circular upstream spigot to the maximum width as the upper surface extends from the circular upstream spigot, a lower surface of the body portion extends linearly from the circular upstream spigot to, and across, the maximum width; wherein a cross-sectional area of an interior of the two-spigot ninety-degree elbow remains largely constant from the circular upstream spigot, across the body including the maximum width, and to the circular downstream spigot.
2. A trap assembly including the two-spigot part elbow of claim 1, wherein the two-spigot elbow connects to the upstream ninety-degree elbow and the downstream ninety-degree elbow to form a drain trap achieving a two inch standard weir height despite the overall height of the trap being shorter than a conventional trap with the same internal cross-sectional area.
3. A method of manufacturing the two-spigot elbow of claim 1, comprising: injecting an upstream portion and separately injecting a downstream portion to form a fitting lip and groove joint; and assembling by cementing together the upstream portion and the downstream portion to form the two-spigot elbow.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) In the drawings, which illustrate embodiments of the invention:
(2) FIG. 1 shows a lateral view of a flat elbow;
(3) FIG. 2 shows a lateral view of a flat trap assembly;
(4) FIG. 3 shows a lateral view of a flat trap assembly attached to a drain hub though a subfloor;
(5) FIG. 4 shows a lateral cross section of a flat trap assembly attached to a drain through a subfloor;
(6) FIG. 5 shows a lateral view of a comparison of a regular trap and a flat trap;
(7) FIG. 6 shows an exploded isometric view of the two component parts of the flattened elbow of the trap; and
(8) FIG. 7 illustrates a method of manufacturing in accordance with the present disclosure.
DETAILED DESCRIPTION OF THE INVENTION
(9) The Invention described herein is a novel flat trap fitting for a plurality of shower drain installation types in which a flat trap assembly is assembled from two ninety degree elbows connected by a flattened 90 degree elbow.
(10) A lateral view of a flat elbow in FIG. 1 shows an upstream spigot 1 leading to a flattened constriction 2 leading to a downstream spigot 3.
(11) A lateral view of a flat trap assembly 30 in FIG. 2 shows a two-spigot flat elbow 4 connected with appropriate adhesive to two conventional ninety degree elbows 5 and 7. An upstream hub 6 on the upstream ninety degree elbow 5 is connected to the flattened ninety degree elbow 4, and at the other end of the elbow 4 is connected to a downstream ninety degree elbow with downstream hub 8. The two hubs are for attachment to upstream and downstream pipe. The three elbows comprise a trap.
(12) FIG. 3 shows a lateral view of the trap assembly 30 attached to a floor drain 9 fitted to a subfloor 10 that suspends a downstream hub 13 attached to a pipe 15 further attached to the trap assembly 30 further attached to a pipe 12. Of particular note is the point of contact 11 between the highest point of the trap and the underside of the subfloor 10. This limitation determines the length of the pipe 15 necessary to connect the trap to the drain.
(13) A lateral cross section of the trap assembly 30 connected downstream to a subfloor-mounted drain is shown in FIG. 4. Of note is the formation of the weir, defined as the height difference 15 between the highest point 16 on the underside of the interior of the upstream lower internal void of the flattened elbow and the lowermost point 14 of the internal void of the higher downstream egress of drain water. The entire purpose of a trap is to set up a weir that traps drainage water to prevent sewer gas rising up from the sanitary sewer. For example weir height is set for standard bathroom fixtures at two inches. This height requirement limits reduction of the overall height of the trap.
(14) The lateral view shown in FIG. 5 illustrates how a standard trap 28 on the left with the same weir height not only drops lower at a bottom 18 of the trap than a bottom 19 of the trap assembly 30 but also rises much higher downstream at 17 than the highest point 20 of the trap assembly 30. This greater height requires greater vertical space for a conventional trap than for the flattened trap. In some cases, the height requirement for the conventional trap may be greater than the space available between an underside 22 of the subfloor 10 and a lower limit 21 of a floor joist. This requires extraordinary accommodation of the trap resulting in either bumps in the ceiling below or the necessity of using a smaller diameter trap. A smaller trap drains less water and contravenes building code.
(15) FIG. 6 shows an exploded isometric view of the flat elbow 4. As can be seen in FIG. 6, the cross-sectional shape of the elbow changes from circular at an upstream spigot 1 to ovoid or rectangular partway downstream returning to a circular shape at the downstream spigot 3. The two parts of the elbow are connectable via a lip 24 insertable into a groove 25. The components would typically be assembled using a suitable adhesive cement. A benefit of the two-part construction is reduced mold costs and an ability to access an interior of the two-part elbow to apply an antimicrobial coating. A suitable antimicrobial coating would be a brass alloy ring inserted into the diameter of the downstream spigot 1.
(16) FIG. 7 shows a method in accordance with the present disclosure. At block 202, the method includes injecting an upstream portion and injecting a downstream portion to form a fitting lip and groove joint. At block 204, an antimicrobial coating is applied. At block 206, the lip and groove joint are cemented together to form an ovoid elbow. At block 208, a ring of antimicrobial brass alloy is inserted in the internal diameter of the downstream spigot.
