Swimming pools have various ways of cleaning the debris which is floating on the surface of the water. One way is to let the water drain into a filter box having a floating weir therein. Another way is to let the water overflow or slosh onto a grate bar system which covers a sump running around the perimeter of the pool. The grate bar system is being installed over the top of the sump. The grate bar system is even with the concrete walk which extends around the pool as a walkway.
The water sloshing over the grate bar system constantly keeps the surface of the grate bar system wet. It also of the utmost importance that the surface of the grate bars are as slippery-proof as possible. There are grate bars having a friction surface made up of ribs that run parallel to the longitudinal extent of the pool and there grate bars that have a friction surface made up of ribs running perpendicular to the longitudinal extent of the pool. The perpendicular ribs have proofed to be most useful because the water in between the ribs tends to empty quicker than the ribs running perpendicular to the pool. However, it has been found that the inventive rib profile is most beneficial in emptying the water between the ribs. The inventive profile consists of angular ribs that are stacked within each other in a certain direction.
Experiments have found that this design is effective in draining water quickly while it reduces the travel time of the water over the grates, thereby preventing mold from forming because of stagnant water. There are no sharp edges which creates comfort under bare feet. The friction design helps to keep the grate bars cleaner because stains are prevented.
It can now be seen that the inventive friction profile has many advantages over the straight ridges known in the prior art.