Trench pan and grate assembly

Abstract

A trench pan and grate assembly generally rectangular in shape, having downwardly ramped transition bottom walls and an integrally-formed but removable strainer plate, terminating in a round pipe receiving fitting that is, through use of a bushing, able to accommodate the common different types of commercially-available plastic plumbing pipe of a given nominal size, and thus be connected to an underlying sloped main drainage pipe. The separate grate member is installed and fastened down, via threaded fasteners, to the trench pan to complete the assembly. This heavy duty grate is formed using gas-assist molding procedures with fractional-melt material (melt number<1.0). Individual assemblies can be formed end-to-end into an elongate trench drain system, with each assembly containing no standing effluent, and connected to different drainage pipes if desired. Assemblies can be solvent welded to drainage piping and thus require nothing to position and hold while the adjacent concrete is being cast.

1 . A high strength injection-molded plastic grate for use with onsite waste and drainage system components, comprising: 
 a generally planar drain member having a plurality of through openings for permitting drainage of fluids therethrough;    a plurality of transverse cross walls connected to the drain member and extending generally downwardly therefrom;    at least one of the transverse cross walls formed to have a molding gas-assist-created void substantially at the interface of that at least one transverse cross wall and the drain member;    a plurality of longitudinal walls connected to the drain member and to the respective transverse cross walls, and extending downwardly from the drain member; and    the grate being formed of fractional melt injection molding material.    
     
     
         2 . The grate of  claim 1 , and wherein at least one of the longitudinal walls is formed to have a molding gas-assist-created void at the interface of that at least one longitudinal wall and the drain member.  
     
     
         3 . The grate of  claim 1 , wherein the fractional melt material comprises HDPE material having a fractional melt between approximately 0.4 and 1.0.  
     
     
         4 . The grate of  claim 1 , and wherein all of the transverse cross walls are formed with a molding gas-assist-created void.  
     
     
         5 . The grate of  claim 1 , wherein the gas-assist-created void of the at least one of the longitudinal walls is of a greater cross-sectional size than the gas-assist-created void of the at least one of the transverse cross walls.  
     
     
         6 . The grate of  claim 1 , and a peripheral edge wall extending downwardly from substantially the perimeter of the planar drain member, and wherein the outer ends of the respective transverse cross walls and longitudinal walls are integrally connected to the edge wall.  
     
     
         7 . The grate of  claim 6 , and a plurality of generally vertically extending, threaded fastener receiving bosses formed along the peripheral edge wall.  
     
     
         8 . The grate of  claim 1 , wherein each of the plurality of through openings is generally of a square shape and not greater than approximately ½ inch by ½ inch.  
     
     
         9 . The grate of  claim 1 , wherein on an underside of the grate, each of the plurality of through openings is isolated by a portion of at least one of the longitudinal walls and a portion of at least one of the transverse walls.  
     
     
         10 . A trench drain component, comprising: 
 an elongate trench pan member having a generally upright peripheral wall, a series of ramped lower walls extending generally downward from the peripheral wall and terminating in a pipe receiving fitting, wherein the length-to-width ratio for the elongate trench pan member is greater than 1:1.    
     
     
         11 . The trench drain component of  claim 10 , and an injection-molded grate member adapted to be received by the trench pan member, the grate member being formed of fractional melt molding material and having gas-assist cavities.  
     
     
         12 . The trench drain component of  claim 11 , wherein the grate is at least approximately 6 inches wide.  
     
     
         13 . The trench drain component of  claim 10 , wherein the length-to-width ratio is at least 2:1.  
     
     
         14 . The trench drain component of  claim 10 , and an adapter fitting operable to be received by the pipe receiving fitting so as to permit connection of at least one given size commonly-available plastic drain pipe segment.  
     
     
         15 . The trench drain component of  claim 14 , wherein the plastic drain pipe segment has a nominal diameter of 4 inches.  
     
     
         16 . The method of forming injection-molded plastic grate components to exhibit substantial impact strength and substantial dimensional stability, comprising the steps of: 
 using an injection mold for forming a grate member having gas-assist internal cavities;    using a fractional melt molding material in the mold; and    using injection molding pressures less than approximately 22,000 psi.    
     
     
         17 . The method of  claim 16 , and the step of forming the grate to measure at least approximately 6 inches in nominal width.  
     
     
         18 . The method of  claim 16 , and the step of forming the grate to have a length-to-width ratio of greater than 1:1.  
     
     
         19 . The method of  claim 16 , and selecting the fractional melt material to be fractional melt high density polyethylene material.  
     
     
         20 . The method of  claim 19 , and wherein the fractional melt is between approximately 0.4 and 1.0.  
     
     
         21 . A trench drain component for use individually or in series, comprising: 
 a trench pan member having a generally upright peripheral wall, a lower pipe receiving opening, and a bottom drain floor formed of ramped drainage walls connecting the peripheral wall to the lower pipe receiving fitting, and the trench pan member further adapted to permit at least two trench pan members to be substantially abutted together, and each separately connected by the lower pipe receiving opening to an underlying drainage pipe, when desired.    
     
     
         22 . The trench drain component of  claim 21 , and a grate member adapted to be received by the trench pan member.  
     
     
         23 . The trench drain component of  claim 21 , wherein the peripheral wall includes: 
 an upper wall portion adapted to surround the grate member;    an intermediate ledge extending inwardly from, and generally perpendicularly to, the upper wall portion; and    a lower wall portion extending downwardly from the intermediate ledge, said lower wall portion disposed inwardly of the upper wall portion, and the bottom drain floor connected to the peripheral wall at a bottom end of the lower wall portion.    
     
     
         24 . The trench drain component of  claim 23 , wherein the intermediate ledge and the lower wall portion define a notch area along an exterior of the trench pan member.  
     
     
         25 . The trench drain component of  claim 23 , further comprising a plurality of upstanding teeth disposed on the intermediate ledge, each of the upstanding teeth being spaced inwardly from the upper wall at least a distance equal to a thickness of an outer perimeter wall of the grate member, said teeth and said upper wall frictionally securing the outer perimeter wall therebetween, whereby the grate member is releasably retained by the trench pan member.  
     
     
         26 . A trench component for use in a trench drain system, comprising: 
 an elongated pan member having an upstanding peripheral wall, a pipe receiving fitting for connection to commonly-available plastic drain pipe, a generally ramped bottom wall extending from the peripheral wall to the pipe receiving fitting, and wherein the length-to-width ratio for the pan member is greater than 1:1.    
     
     
         27 . The trench component of  claim 26 , and a strainer member formed substantially across one end of the pipe receiving fitting.  
     
     
         28 . The trench component of  claim 27 , wherein said strainer member is removably connected across said one end of the pipe receiving fitting by a plurality of reduced thickness connection segments, said reduced thickness connection segments being breakable to facilitate removal of the strainer member from the end of the pipe fitting.  
     
     
         29 . The trench component of  claim 26 , and a grate member adapted to mount the trench pan, the grate being formed of fractional melt injection molding material.  
     
     
         30 . The trench component of  claim 26 , and wherein the grate is formed to have gas-assist chambers.