ELEVATOR TRENCH DRAIN

Abstract

A trench drain includes a trench, a grating seat and a grating hingedly connected to the trench. The trench has a base wall with peripheral side walls extending upwardly therefrom and an outwardly-extending peripheral flange. The grating seat is configured to receive the grating. The peripheral side walls of the trench have a pair of opposing elongated slots formed therein and the grating has a pair of posts on opposing ends thereof. Each of the pair of posts on the grating are received in a respective one of the pair of opposing elongated slots of the trench to establish an axis of rotation.

Claims

1. A trench comprising: a trench having a base wall with peripheral side walls extending upwardly therefrom and an outwardly-extending peripheral flange; a grating seat disposed between an upper peripheral lip and the base wall; and a grating hingedly connected to the trench; wherein the grating seat is configured to receive the grating and the peripheral side walls of the trench have a pair of opposing elongated slots formed therein and the grating has a pair of posts on opposing ends thereof and wherein each of the pair of posts on the grating are received in a respective one of the pair of opposing elongated slots of the trench to establish an axis of rotation.

2. The trench of claim 1, wherein axial twisting of the axis of rotation aligns the posts relative to the slots for a hinged connection between the grating and the trench.

3. The trench of claim 2, wherein the grating is opened at the hinged connection.

4. The trench of claim 1, wherein the grating and the grating seat are rectangularly shaped.

5. The trench of claim 1, wherein the grating includes a grid having a plurality of lengthwise extending bards joined to a plurality of widthwise extending supports.

6. The trench of claim 5, wherein the grid includes a plurality of shapes formed by the lengthwise extending boards and the widthwise extending supports.

7. The trench of claim 1, wherein the grating is made of a stainless steel wire grating.

8. The trench of claim 1, wherein the grating includes an open area of grating.

9. The trench of claim 8, wherein the open area is 64.9 square inches per linear foot of grating.

10. The trench of claim 8, wherein the open area is 35.9 square inches per linear foot of grating.

11. The trench of claim 1, wherein the grating has a height of 29/32 inches.

12. The trench of claim 1, wherein the grating has a width of 11.375 inches.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0018] FIG. 1 is a perspective view of an elevator trench drain in which a grating is closed over the trench.

[0019] FIG. 2 is a perspective view of the elevator trench drain of FIG. 1 in which a grating is hinged open, revealing the inner volume of the trench and the top side of the drain passageway.

[0020] FIG. 3 is a detailed exploded book view of one side the hinge connection between the grating and the trench illustrating how the post of the grating is received in the slot of the trench.

[0021] FIG. 4 is a detailed cross-sectional side view of the drain passageway of the elevator trench drain illustrating the reduction in cross-sectional area from the top section to the bottom section of the drain passageway.

[0022] FIG. 5 is a detailed top view of drain passageway further illustrating the profile of the upper and lower sections of the drain passageway as seen from above.

DETAILED DESCRIPTION

[0023] Referring first to FIGS. 1 and 2, an elevator trench drain 10 is illustrated in closed and opened positions, respectively. An elevator trench drain of this type is designed to be installed along the width of the lower edge or threshold of an elevator door. This drain can provide a drainage pathway for fluids, for example water from sprinkler systems. In the absence of such a drain in a situation in which a sprinkler system has been activated, water from the system might collect on the floor and potentially drain into the elevator or elevator shaft. If that were to happen, the elevator system could malfunction in the event of an emergency or be otherwise damaged.

[0024] The elevator drain 10 is generally rectangular in the exemplary form shown; however, in other forms, the elevator trench drain 10 may have generally different shapes or aspect ratios which may be custom to the particular application. Because the exemplary elevator trench drain 10 is rectangular, it extends between a pair of lateral ends 12 and 14 which define an overall length of the assembly and extends between a pair of forward and backward ends 16 and 18 which define an overall width of the assembly.

[0025] In the illustrated assembly, the elevator trench drain 10 has two main parts including a trench 20 and a grating 22. During use, the water will flow through the grating 22 and collect in the trench 20, though which the water is subsequently drained or evacuated.

[0026] The trench 20 has a base wall 24 with peripheral side walls 26 extending upwardly from the base wall 24. Because the particular drain 10 is rectangular, the peripheral side walls 26 include a pair of lateral side walls 28 and 30, a front wall 32, and a rear wall 34. In aggregate, the various walls of the trench 20 defining a trench volume 36 inside the trench 20. In the instant case, this trench volume 36 is generally rectangular in shape being established by the base wall 24, the pair of lateral side walls 28 and 30, the front wall 32, and the rear wall 34.

[0027] The various peripheral side walls 26 of the trench 20 also include an inwardly extending step 38 between an upper peripheral lip 40 and the base wall 24 that defines a grating seat 42 for the reception of the grating 22. In the form illustrated, this step 38 occurs approximately halfway between an upper surface 44 of the upper peripheral lip 40 and the base wall 24. During use, water flowing into the trench 20 may also collect (at least to some extent) in the trench volume 36 partially occupied by the grating 22.

[0028] The trench 20 may also include features that assist in the installation of the elevator trench drain 10 into the floor, although such features may not be found in all designs. In the particular form illustrated, the trench 20 includes an outwardly-extending peripheral flange 46 that is offset slightly downward from the upper peripheral lip 40. This peripheral flange 46 may receive floor coverings (for it, carpet, tile, cast materials such as concrete) over it such that the top of the floor covering is roughly flush with the upper surface 44 of the upper peripheral lip 40. There may also be anchor straps 48 that extend outwardly past the flange 46 which are employed during the installation of the trench 20 into the surrounding building structure.

[0029] With brief forward reference being made to FIG. 3, to hingedly receive the grating 22 in the trench 20, each of the lateral side walls 28 and 30 may include a slot 50 formed therein such that the slots 50 collectively define a pair of opposing slots. In the particular form illustrated in FIG. 3, the slot 50 is formed above the step 38 in the lateral side walls 28 and 30 proximate the rear wall 34. To accommodate entry of the respective post 52 on the grating 22, these slots 50 are elongated in the front to rear direction such that the grating 22 may be slightly twisted relative the trench 20 and the eventual hinged axis of rotation to provide sufficient clearances for assembly of the posts 52 into the slots 50. In the form illustrated, the slots 50 are integrally formed in the peripheral side walls 26 of the trench 20 and are formed by a wall 54 that extends generally perpendicularly from the peripheral side wall 26 of the trench 20 and forms a closed loop that establishes the slot 50.

[0030] With particular reference now being made to FIG. 4, the trench 20 includes a drain passageway 56 that extends downwardly the base wall 24 of the trench 20. As illustrated, the drain passageway 56 is centrally located along the width and length of the trench 20. However, it is contemplated that the drain passageway 56 might be located otherwise such as, for example, at one end of the base wall 24 of the trench 20 or offset from center in one or both of the length and width directions. This drain passageway 56 places the trench volume 36 (at an upper opening 58 formed in the base wall 24) in fluid communication with a lower opening 60 of the drain passageway 56. The lower opening is typically connected in use to a drain pipe such as a 4 inch drain pipe for further routing of the drained water.

[0031] As best seen in FIGS. 4 and 5, the drain passageway 56 has multiple sections as it extends downwardly from the upper opening 58 to the lower opening 60. In the particular form illustrated, there are three sections including an upper section 62 proximate the upper opening 58 in the base wall 24, a lower section 64 proximate the lower opening 60 of the drain passageway 56, and an intermediate section 66 between the upper section 62 and the lower section 64. The upper section 62 and the lower section 64 each have a constant respective cross-sectional area over their axial height or distance of extension. In the illustrated embodiment, the upper section 62 is circular having a diameter of 6 inches and the lower section 64 is circular having a diameter of 4 inches (to match standard drain pipe which is connected to the outlet). The intermediate section 66 between the upper section 62 and the lower section 64 includes an approximately 45 degree taper that transitions the diameter between the respective sections 62 and 64 above and below it. Although the taper is illustrated as extending entirely from the first section to the second section, it is contemplated that there may be more than one differently angled tapered regions or radially extending step in this intermediate section. While circular cross-sections are found in the illustrated design as can be best seen in FIG. 5, it is contemplated that other drain cross sections might also be used if those reduce in cross-section area from the upper section to the lower section.

[0032] Among other things, the profile of this drain passageway 56 helps to improve the flow rate of water collecting in the trench 50 through the drain passageway 56. The upper section 62 creates a head pressure which causes the acceleration of the water flowing downward into the lower section 64. Although it is contemplated that the intermediate section 66 might be omitted (i.e., that there could simply be a flat step between sections 62 and 64 which is perpendicular to the central axis of the drain passageway 62), the taper or angling of the intermediate section 66 can further enhance the flow from the upper section 62 to the lower section 64 because it assists in directing the flow of the water in a non-turbulent manner from the upper section 62 into the lower section 64. Among other things, the reduction in diameter to improve and increase flow rate can help enable a low profile (i.e., thin) design so that the elevator trench drain 10 may be installed in smaller spaces without increasing the depth of the floor to accommodate for the drain.

[0033] Some exemplary and non-limiting dimensions are now provided for the trench 20. The height of the trench 20 is contemplated as being typically 1.75 inches overall (exclusive of the drain passageway 56), although other depths may also be used depending on the installation context or needs of the customer. A typical width may be 13.5 inches overall with an 11.4375 inch grating seat area. The finished perimeter flange may be approximately 1 inch from the upper peripheral lip 40. The overall length of channel may typically be in a range of 38 to 120 inches. The drain passageway 56 is illustrated as being hydraulically engineered from 6 inches to 4 inches in a funnel style outlet to increase head pressure on the 4 inch section to promote flow (with flow in excess of 100 gallons per minute being targeted in many conditions to meet code and achieved using this passageway structure). This ratio of the diameters from the first section to the second section is approximately 1.5 (6 inches to 4 inches), but it is contemplated that other similar ratios may also be used, for example, in the range of 1.3 to 1.7 or more narrowly in the range of 1.4 to 1.6. The entire trench construction may be provided in Type 304 stainless steel but may also be in Type 316 stainless steel in certain applications or based on customer preference.

[0034] The grating 22 is also generally rectangular in shape to match and fit into the grating seat 42 of the trench 20. The exemplary grating 22 includes a first plurality of lengthwise-extending bars 68 which are joined to a second plurality of widthwise-extending supports 70 to form a grid. However, in other forms, the grating pattern may be different or otherwise embellished to provide a desired aesthetic appearance. On the rear side of the grating 22, there are a pair of oppositely facing posts 52 that are located for reception into the slots 50 of the trench 20 as illustrated in FIG. 3. FIGS. 3 and 4 also illustrate that each of the first plurality of lengthwise-extending bars 68 includes a bottom surface 100, facing and positioned a first distance 102 from the base wall 24, a top surface 104, opposite the bottom surface 100 and spaced a second distance 106 from the base wall 24 greater than the first distance, and a pair of side surfaces 108 extending between the bottom surface 100 and the top surface 104. As shown in FIG. 3, the side surfaces 108 are sub-divided into two portions 112, 116. The lower portion 112 of the side surface 108 is oriented substantially parallel to the front or first wall 32 and the upper portion 116 of the side surface 108 is oriented oblique to the front wall 32. More specifically, FIG. 3 shows that the upper portion 116 of the side surfaces 108 are oriented oblique to the front wall 32 in a vertical orientation (e.g., measured vertically). FIG. 3 also illustrates that each of the lengthwise extending bars 68 include a lower edge 120 where the bottom surface 100 meets the side surface 108 and an upper edge 124 where the top surface 104 meets the side surface 108. In the illustrated embodiment, the lower edge 120 is spaced a second distance 106 from the base wall 24 while the upper edge 124 is spaced a first distance 102 from the base wall 24 that is greater than the second distance 106. FIGS. 1 and 3 also show that the upper edge 124 is both parallel to and positioned closer to the front wall 32 than the lower edge 120. The lower edge 120 is also parallel the front wall 32. Each bar 68 also defines a longitudinal axis 132 therethrough that is oriented parallel to the front wall 32.

[0035] As noted above, by angularly twisting the axis of the posts 52 (which are co-axial with one another) they can be slid into the slots 50 of the trench 20 to provide a hinged connection to open the grate as generally illustrated in FIG. 2. There may be some range of motion restrictions depending on the depth of the grating seat 42 and the placement of the posts 52 on the grating 22.

[0036] The grating 22 may be a stainless steel wire grating and may be approximately 2 inches shorter than the specified channel length to accommodate installation of the grating 22 into the trench 20 and provide some side clearances. As with the trench 20, the grating 22 may be manufactured from Type 304 stainless steel or Type 316 stainless steel. In one exemplary form, the grating 22 may features an open area of 64.9 square inches per linear foot of grating. Wires, bars, and supports may be held by press fit and welded to support trusses (i.e., the bars 68 may be press fit and welded into supports 70 or vice versa). Some gratings may be a fabricated stainless steel slotted grate with an open area of 35.9 square inches per linear foot. In some forms, grating height may be 29/32 inches tall and grating width may be 11.375 inches wide.

[0037] Accordingly, an elevator trench drain is disclosed that accommodates high flow rates (up to and exceeding 100 gallons per minute) without having a deep trench depth or necessarily having multiple outlets to accommodate slower flows. The improved drain passageway permits high flow rates without compromising other dimensions of the product or complicating the drain system with additional, multiple fluid connections.

[0038] It should be appreciated that various other modifications and variations to the preferred embodiments can be made within the spirit and scope of the invention. Therefore, the invention should not be limited to the described embodiments. To ascertain the full scope of the invention, the following claims should be referenced.