The present invention relates to drainage grates used in connection with trench drains and the like for the drainage of surface water. Trench drains and similar drainage structures are used in a variety of environments, such as walkways, bike and foot paths, outdoor malls, parking lots, airport tarmacs and other traffic environments which require the drainage of surface water. Trench drains and drainage structures generally are known in the art as described in, for example, U.S. Pat. Nos. 4,630,966; 4,699,544; 5,462,382 and 4,553,874, incorporated herein by reference. In order to provide access of surface water to the drainage structure, while at the same time enabling practical movement of traffic across the structure, apertured drainage grates are typically employed to provide a substantially continuous surface over which pedestrian or vehicle traffic can freely move.
Drainage grates are typically made of varying gauges of sheet metal and are, therefore, subject to damage. Dents, buckles and perforations in the drainage grate are not only aesthetically undesirable, but are also safety concerns which can lead to injury to pedestrians and damage to surface vehicles. Accordingly, drainage grates must meet particular load ratings depending upon the environment in which they are to be used. Although there is no universal system for load rating of trench drains, the internationally recognized DIN 19580 standard, incorporated herein by reference, provides a good basis on which to distinguish between classes. Basically, for trench drains under 8 inches wide, a class A rating will withstand 15 psi within the standard 3 inch by 10 inch load footprint, and is typically used in residential and light pedestrian areas. A class B rating will withstand 140 psi in the load footprint, and is typically used for sidewalks and small private parking lots. A class C rating will withstand 280 psi in the load footprint and is appropriate for commercial parking lots and the like. Classes D and above will withstand 450 psi or more in the load footprint and are found in roads or other areas experiencing heavy wheel loads.
The requirement for different load ratings typically means that a manufacturer must provide different grates for different applications. Thus, in practicality, a manufacturer must provide grates of different gauges and materials or which include various reinforcements appended thereto. However, there are practical limits to the gauges of metal which can be used and, even when various reinforcements are included, they often do not provide support to all or most of the vulnerable portions of the drainage grate surface. Thus, even a reinforced grate is still subject to damage in those regions which are not directly reinforced.
In view of the foregoing shortcomings, the present invention advantageously provides a reinforced drainage grate which is capable of providing support to all or most of the drainage grate surface, and which can provide a wide range of load ratings without having to manufacture and inventory different grates for each desired load rating.
In accordance with the invention there is provided an improved drainage grate assembly which provides improved reinforcement and enables the use of varying gauges of sheet metal where other, more durable and costly materials such as cast iron might otherwise be required. Moreover, the instant invention is advantageously capable of providing substantially continuous support and reinforcement to the entire drainage grate.
Accordingly, in one embodiment of the invention there is provided a reinforced drainage grate assembly comprising an elongate drainage grate having a substantially planar drainage surface including a plurality of apertures therethrough and a pair of longitudinally extending side portions, each side portion extending orthogonally below an underside of said drainage surface and including a bottom flange extending toward the opposing one of said side portions. The drainage grate assembly further includes a first reinforcement retaining rail disposed between a first of the bottom flanges and the underside of the drainage surface adjacent a first of said side portions, and a second reinforcement retaining rail disposed between the other of the bottom flanges and the underside of the drainage surface adjacent the opposing said side portion. Each retaining rail is an elongate member which, when assembled, comprises a back surface adjacent a side portion, a bottom surface adjacent a bottom flange, a top surface adjacent the underside of the drainage surface, and a front surface facing the opposing retaining rail. Further, each front surface includes a plurality of slots adapted to receive an end of a reinforcing strip, whereby when opposing ends of a reinforcing strip are disposed within slots in opposing retaining rails, the upper edge of the reinforcing strip abuts at least a portion of the underside of the drainage surface.
In carrying out the invention the assembly preferably includes a plurality of reinforcing strips having opposed ends disposed within the slots in the opposed retaining rails. More preferably, the slots comprise a recess disposed in the front surface and extending through said bottom surface. More preferably still, a portion of the upper surface adjacent the slots includes an aperture extending from the upper surface into the slot which is adapted to receive a portion of an upper edge of a reinforcing strip therein, whereby the portion of the upper edge abuts the underside of the drainage surface when the reinforcing strip is disposed in the slot so as to provide metal-to-metal contact therewith.
In other aspects of the invention, the assembly includes reinforcing strips having at least two different configurations. In a preferred embodiment, the assembly includes reinforcing strips that are a substantially flat strip of sheet metal and reinforcing strips that are shaped to form a substantially sinusoidal configuration when viewed on edge.
In a further aspect of the invention the assembly includes an elongate fastening member secured between the retaining rails and oriented substantially orthogonally from the underside of the drainage surface. The elongate fastening member includes an enlarged distal end portion adapted to cooperate with a receiving member in the drainage channel and secure the drainage grate assembly thereto. In a preferred embodiment, the elongate fastening member includes an upper portion adjacent the underside of the drainage surface which is secured between the retaining rails by abutment of the upper portion against upper edge portions of at least one of the reinforcing strips.
A greater understanding of these and other aspects of the invention will be had from the following detailed description and accompanying drawings.
As seen with reference to the drawings, the preferred drainage grate assembly of the invention comprises an outer drainage grate, shown generally at 1, a pair of retaining rails 20 and a plurality of reinforcing strips 30. As discussed in more detail below, the retaining rails 20 and reinforcing strips, when assembled, cooperate to form a reinforcing assembly, shown generally at 40.
As seen most clearly with reference to
Typical metal gauges suitable for use in the manufacture of drainage grates according to the invention will be on the order of 3 millimeters or less, and more preferably 2 millimeters or less. The particular type of sheet metal used will depend upon application and aesthetic requirements, although sheet steel is generally preferred. The particular gauge used will depend upon various factors including cost and grate width, with wider grates generally requiring thicker gauges. Of course, the reinforcing strips of the present invention advantageously enable the use of thinner and hence less costly gauges. Selection of suitable materials will be within the level of ordinary skill in the art in view of the instant disclosure. Likewise, the stamping, rolling and bending processes used to fashion the drainage grates according to the invention are also well within the skill in the art. Accordingly, as will be apparent to those of ordinary skill in the art reading the instant disclosure, any standard metal shaping technique known in the art will be suitable for making and shaping the drainage grates according to the instant invention.
As seen in
As seen best in
Each retaining rail 20 further includes a plurality of slots 25 for receiving an end portion of a reinforcing strip 30. In the preferred embodiments, the slots 25 comprise recesses or grooves disposed in the front surface 24 and extending through the bottom surface 22, best seen in
In the preferred embodiment shown, the retaining rails 20 further include apertures 26 disposed in the top surface and extending into the slots 25. Apertures 26 advantageously enable the provision of enhanced support to the drainage grate surface in the region adjacent the retaining rails 20. More specifically, apertures 26 are configured to receive an upper edge portion 35′ of a reinforcing strip 30 when an end portion of a reinforcing strip 30 is disposed within slot 25, thereby providing metal-to-metal contact between the upper edge surface 35′ of the reinforcing strip and the bottom surface 9 of the drainage grate in the region adjacent the reinforcing rails.
The retaining rails 20 are preferably made of plastic. Suitable plastics for use in the invention will be apparent to those of ordinary skill in the art in view of the instant disclosure. Preferably, the plastic is polyvinyl chloride (PVC), high density polyethylene (HDPE) or polypropylene. The retaining rails 20 can be molded or extruded and machined using well known plastic manufacturing techniques within the level of skill in the art in view of the instant disclosure. The retaining rails 20 are preferably injection molded.
The metal reinforcing strips can be of any suitable dimension so long as they fit within slots 25 and are capable of spanning the inner diameter of the drainage grate, so that their respective end portions can be retained within the slots 25 of the respective retaining rails 20. A preferred metal strip according to the invention, shown general at 30 in
As seen in
In the preferred embodiment shown in the drawings, end reinforcing strip 130 has a generally sinusoidal configuration adapted to snake around a line of apertures so as to provide support to the drainage surface on both sides thereof. Other than being bent to include aperture accommodating regions 133, the end reinforcing strip 130 includes an upper edge surface 135 and notches 136 for providing metal-to-metal contact and support to the underside of the drainage surface 3, shoulder portions 132 for cooperating with the retaining rails, and an enlarged body portion 134 to provide enhanced support to the central region of the drainage grate, all as described above in connection with reinforcing strip 30.
In order to secure the drainage grate assembly to a trench drain, some embodiments will employ a thru-bolt extending through the drainage grate 1 and reinforcing assembly 40. Although one could simply eliminate reinforcing strips from the region of the reinforcing assembly which must accommodate the thru-bolt, this could undesirably leave portions of the drainage surface unsupported. Accordingly, additional reinforcing strip configurations may be employed to accommodate a thru-bolt or other securing mechanism. Again, the object is to configure the reinforcing strip used for this application to accommodate the thru-bolt or other securing mechanism while at the same time providing as much support to the drainage surface as possible.
A preferred reinforcing strip 230 is shown in
More specifically, reinforcing strip 230 can be disposed in the retaining rails such that the aperture 238 will correspond to and be co-registered with a corresponding thru-bolt aperture 13 (
A preferred means of securing the drainage grate assembly of the invention to the trench drain channel is described in European Patent No. 0605792. Briefly, as seen in connection with
A disadvantage of having to employ either a thru-bolt or a thru-pin is the need for the additional thru-bolt or thru-pin aperture 13 and the need to form a recess 15 (
As will be apparent to one of ordinary skill in the art in view of the instant disclosure, there are numerous configurations which will accomplish this function. For example, the base end of the securing member 42 and/or pin 41 can comprise or be secured to a generally rectangular block or an enlarged flange which is held in place by the upper edges 35 of the substantially flat reinforcing strips 30 being modified to fit around the base end of the member 42 or pin 41. However, such configurations have the disadvantage of not having any reinforcing strip surfaces in abutment with the underside of the drainage surface on either side of the securing member between the member and the rails. Thus, for example, one could employ two end reinforcing strips 130 adjacent one another and arranged such that aperture accommodating regions 135 accommodate a thru-bolt disposed therebetween. One of ordinary skill in the art will be able to select suitable reinforcing strip configurations for any particular aperture configuration in view of the instant disclosure.
In a preferred embodiment, the reinforcing rails 20 and the desired number and gauge of reinforcing strips 30, 130, 230 are assembled to form reinforcement assembly 40 separately from the drainage grate 1, which is likewise formed and shaped separately. The reinforcing assembly 40 is thereafter inserted longitudinally into the drainage grate 1 and secured in place. Alternatively, the drainage grate 1 can be formed and then shaped around the assembled reinforcing assembly 40, whereafter the reinforcing assembly 40 is secured in place within the drainage grate 1. The reinforcing assembly can be secured within the drainage grate by any means which does not interfere with its ability to properly seat within a drainage channel. Suitable means can include mechanical fasteners or the provision of additional flange portions at opposite ends of the grate 1 which can be bent over, or otherwise cooperate with the opposed end strips 130 of the reinforcing assembly 40 to secure the assembly in place. In the preferred embodiment, the retaining rails 20 includes one or more detents 28, in their bottom surfaces 22 adjacent the flange portions 7, whereby the reinforcing member is secured within drainage grate 1 by a simple crimping or stamping action on the portion of the flanges 7 adjacent the detents 28.
As will be apparent to those of ordinary skill in the art, depending upon the number and/or gauge of the metal reinforcing strips present in slots 25, the reinforcing strength of reinforcing assembly 40, and hence the load rating of the drainage grate 1 will vary. As a general rule, the thicker the gauge and/or the larger the number of metal strips, the higher the load rating will be. Typical gauges for strips used in accordance with the invention will generally be two millimeters or less. Where it is desired to stock thinner gauge strips, multi-tiered slots may be employed which can securely accommodate a single strip or multiple strips disposed side-by-side within a single slot 25 to achieve the desired effect. In carrying out the invention, one can theoretically obtain load ratings ranging from Class A to Class D or E using the reinforcing assembly 40 of the invention, although other means of reinforcement and or different materials will generally be used to obtain ratings above Class C. However, as load ratings and test methods may vary throughout the world, those of ordinary skill in the art will recognize that the invention does not lie in the ability to achieve any particular standard or specific test specification. Rather, the invention lies in the provision of a reinforcing member which provides a means by which one of ordinary skill in the art can tailor the support provided to any particular drainage grate to any desired load requirements and obtain substantially continuous support.
In the preferred embodiments according to the invention, best seen in
Modifications and variations of the invention will be apparent to those skilled in the art in the light of the foregoing detailed disclosure and drawings. Therefore, it is to be understood that, with the scope of the appended claims, the invention can be practiced otherwise than shown and described.
Number | Name | Date | Kind |
---|---|---|---|
1426736 | Hess | Aug 1922 | A |
1428230 | Hess | Sep 1922 | A |
2031779 | Ladd | Feb 1936 | A |
2084118 | Zabriskie | Jun 1937 | A |
2396735 | Leigh | Mar 1946 | A |
2917804 | Barron | Dec 1959 | A |
3228679 | Dees | Jan 1966 | A |
4007566 | Molitor | Feb 1977 | A |
4337005 | LeBaron | Jun 1982 | A |
4367142 | Blecher | Jan 1983 | A |
4844655 | Aleshire | Jul 1989 | A |
4909660 | Ferns | Mar 1990 | A |
4981395 | Datin et al. | Jan 1991 | A |
5024550 | Mainville | Jun 1991 | A |
5130016 | Gavin | Jul 1992 | A |
5443327 | Akkala et al. | Aug 1995 | A |
5463786 | Mangone et al. | Nov 1995 | A |
5518339 | Shimizu | May 1996 | A |
5538361 | Beamer | Jul 1996 | A |
5733445 | Fanelli | Mar 1998 | A |
6349656 | Mitchell | Feb 2002 | B1 |
6595720 | Humphries et al. | Jul 2003 | B2 |
6631588 | Distler | Oct 2003 | B1 |
20040163342 | Marks | Aug 2004 | A1 |
Number | Date | Country |
---|---|---|
2209782 | May 1989 | GB |