Patent ID: 9593489
Date: 2017-03-14
CPC Classifications: E04F

Claim:
1. A tread for a steel-pan staircase comprising: a lattice structure comprising a plurality of longitudinal members and a plurality of crosswise members, the lattice structure further comprising a front side, a rear side, a top side, a bottom side, a left side, and a right side, wherein the longitudinal members extend from the left side to the right side, parallel to a longitudinal axis of the tread, and the crosswise members extend from the front side to the rear side, perpendicular to the longitudinal axis of the tread; a planar top surface integrally formed on the top side of the lattice structure, the planar top surface covering the plurality of longitudinal members and the plurality of crosswise members; and two tongue-and-groove structures, one disposed on the left side, and one disposed on the right side, of the lattice structure, wherein each tongue-and-groove structure comprises only one tongue and only one groove, where one tongue-and-groove structure extends along an entirety of the left side, from the front side to the rear side, and one tongue-and-groove structure extends along an entirety of the right side, from the front side to the rear side, and where one tongue-and-groove structure has a groove open to a top of the tread and one tongue-and-groove structure has a groove open to a bottom of the tread; whereby each tongue-and-groove structure facilitates a joining of the tread to an other, similar tread, and prevents a longitudinal separation of the tread from the other, similar tread.