Underlayment panel having drainage channels

Abstract

An impact-absorbing assembly includes a covering layer being one or more of artificial turf, rubber mats, polymer mats, short pile carpeting, particulate infill, wood chips, and ground rubber chips. Also included is a layer of underlayment panels positioned beneath the covering layer. The panels have a panel section with a plurality of drain holes formed therethrough. A top surface of the panels is configured to support the covering layer. A bottom surface of the panels has a plurality of bottom projections that cooperate to define bottom channels suitable to permit water flow across the bottom surface, the bottom channels being in fluid communication with the panel drain holes. The bottom projections define a first spring rate characteristic that is part of a first stage and a second spring rate characteristic is part of a second stage, the first stage having a smaller volume of material than the second stage.

What is claimed is: 
     
         1 . An impact absorption panel having a first surface, a second surface opposite the first surface, and edges, a plurality of drain holes connecting the first surface in fluid communication with the second surface, at least one of the edges including an interlocking dovetail projection and recess connection configured to mate with and retain an abutting panel, the first surface including a plurality of hexagonal projections defining drainage channels that intersect with the plurality of drain holes, wherein the panel is made of an expanded bead, polyolefin material, the expanded beads bonded together by at least one of heat or pressure, the polyolefin material providing a critical fall height in a range of about 2.5 meters to about 3.0 meters. 
     
     
         2 . The impact absorption underlayment panel of  claim 1  wherein the first surface is a top surface in contact with one of an artificial turf layer, an infill material, or a playground surface material. 
     
     
         3 . The impact absorption underlayment panel of  claim 1  wherein the first surface is a bottom surface in contact with a supporting substrate layer. 
     
     
         4 . The impact absorption underlayment panel of  claim 1  wherein the second surface includes a plurality of projections defining drainage channels that are in fluid communication with drainage holes and drainage channels of the first surface. 
     
     
         5 . The impact absorption underlayment panel of  claim 4  wherein the first layer is a top surface layer and the second surface is a bottom surface including a plurality of projections in contact with a supporting substrate layer, the bottom surface projections defining drainage channels that intersect with at least some of the plurality of drain holes. 
     
     
         6 . An impact absorption underlayment panel having a first surface in contact with one of a covering layer or a substrate layer, a second surface opposite the first surface, and edges, a plurality of drain holes connecting the one of a covering layer or a substrate layer in fluid communication with the second surface, at least one of the edges having interlocking projections extending therefrom, the interlocking projections forming a gap between the at least one edge and a mating edge of an abutting panel, the gap providing a second drainage path between the first surface and the second surface, wherein the panel is made of an expanded bead, polyolefin material, the expanded beads bonded together by at least one of heat or pressure. 
     
     
         7 . The impact absorption underlayment panel of  claim 6  wherein the first surface is a top surface in contact with the covering layer, the covering layer configured as one of an artificial turf layer or an infill material layer, and the second surface is a bottom surface. 
     
     
         8 . The impact absorption underlayment panel of  claim 7  wherein the bottom surface includes a plurality of bottom projections in contact with the substrate layer, the bottom projections defining drainage channels that intersect with at least some of the plurality of drain holes. 
     
     
         9 . The impact absorption underlayment panel of  claim 6  wherein the first surface is a bottom surface in contact with the substrate layer, and the second surface is a top surface. 
     
     
         10 . The impact absorption underlayment panel of  claim 6  wherein a plurality of top projections contacts the covering layer, the top projections defining drainage channels that intersect with at least some of the plurality of drain holes. 
     
     
         11 . The impact absorption underlayment panel of  claim 10  wherein the drainage channels are in fluid communication with the gap. 
     
     
         12 . The impact absorption panel of  claim 6  wherein the covering layer comprises one of a rubber mat or a polymer mat; and
 the first surface includes a plurality of hexagonal projections extending across the first surface and in contact with the covering layer. 
 
     
     
         13 . The impact absorption panel of  claim 6  wherein the first surface includes a plurality of hexagonal projections extending across the first surface, the hexagonal projections in contact with the substrate layer, the second surface supporting one of an artificial turf carpet, a rubber mat, or a particulate layer.