An underlayment layer is configured to support an artificial turf assembly. The underlayment layer comprises a core with a top side and a bottom side. The top side has a plurality of spaced apart, upwardly oriented projections that define channels suitable for fluid flow along the top side of the core when the underlayment layer is positioned beneath an overlying artificial turf assembly.

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.

Embodiments are directed to protecting an elevator. A plurality of knobs may be provided, each respective knob comprising a respective base having a vertical portion, a horizontal portion, a suspension portion, and a face that are coupled to each other. Each knob may also comprise a respective stem coupled to the face of the respective base. The knobs may be hung from an upper edge of a wall panel or suspended ceiling grid in an elevator. A cover may be provided, the cover having a plurality of openings in the cover disposed along the upper edge of the cover. The cover may be hung from the knobs with each knob having the distal end portion of the respective stem extending through a respective one of the openings in the cover.

An ergonomic modular ergonomic multi-layer platform with a synthetic tapered marginal border including a non-compressible wood base covered with at least one compressible mat disposed between the wood base and a top non-slip mat to provide occupational workers with a therapeutic, forgiving work surface to protect them from the health risks of working, walking and standing on a concrete floor or common anti-fatigue mat used in many factories today. The therapy platform is raised off the floor to offer suspension, thus promoting a spring effect for absorbing and returning compression force resulting in reduced stress loads and compression force for people who work, walk or stand fort extended periods of time. The therapy platform is modular in design so that the tapered borders of separate modular sections connect for a snug fit. The vertical edges of the wood sections also have connection points that provide a leveling effect and further enhance the fit of the module sections.

An underlayment layer is configured to support an artificial turf assembly. The underlayment layer comprises a core with a top side and a bottom side. The top side has a plurality of spaced apart, upwardly oriented projections that define channels suitable for fluid flow along the top side of the core when the underlayment layer is positioned beneath an overlying artificial turf assembly.

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.

Various embodiments for a panel that may be combined with other similar panels to form a padding layer of an athletic field, or other surface, are disclosed. The panel for use in a padding layer of a panel system includes a male locking element configured to form a dove-tail connection with at least one adjacent panel. The dove-tail connection includes a male locking element of the panel coupling with a female locking element of the at least one adjacent panel and forming an interference fit between the male locking element and the female locking element. A space is proved between the male locking element and the female element when coupled that permits thermal expansion of the panel.

An underlayment layer is configured to support an artificial turf assembly. The underlayment layer comprises a core with a top side and a bottom side. The top side has a plurality of spaced apart, upwardly oriented projections that define channels suitable for fluid flow along the top side of the core when the underlayment layer is positioned beneath an overlying artificial turf assembly.

A hermetic seal between an optical element and a metal mount or housing using a fluoropolymer. The fluoropolymer is dispersed along the interior edge of the metal mount. The metal mount and fluoropolymer are then heated to a temperature exceeding the melting point of the fluoropolymer. Once heated the optical element is pressed into the metal mount and allowed to cool. The metal mount, optical element and thickness of fluoropolymer are sized to provide an interference fit between the metal mount and optical element.

Various embodiments for a pad that may be combined with other similar pads to form a padding layer of an athletic field, or other surface, are disclosed. The pad includes a top surface and a bottom surface. Bottom-side projections are positioned on the bottom surface of the pad. Water channels are positioned on the bottom surface of the pad defined as a recessed area between individual ones of the bottom-side projections. A drainage hole is positioned in at least one of the bottom-side projections such that the drainage hole does not connect with any of the water channels on the bottom surface. The drainage hole may be at least partially coupled to projection channels on the bottom-side projections, where the projection channels act as a water vacuum to facilitate air circulation and vertical water evacuation relative to the drainage hole.