Abstract: A channel for fluid flow comprising a first unit and a second unit connected to each other. The first unit comprises a first u-section having a first open top side, and a first grate extending across the first open top side and removably attached to the first u-section. The second unit comprises a second u-section having a second open top side, and a second grate extending across the second open top side and removably attached to the second u-section. The first grate defines a negative semicircular distal end having a first diameter and a first center point. The second grate defines a positive semicircular proximal end having a second diameter and a second center point. The first center point is coincident with the second center point and the first diameter and the second diameter are sized such that the positive semicircular proximal end fits within the negative semicircular distal end.

Abstract: A channel for fluid flow comprising a first unit and a second unit connected to each other. The first unit comprises a first u-section having a first open top side, and a first grate extending across the first open top side and removably attached to the first u-section. The second unit comprises a second u-section having a second open top side, and a second grate extending across the second open top side and removably attached to the second u-section. The first grate defines a negative semicircular distal end having a first diameter and a first center point. The second grate defines a positive semicircular proximal end having a second diameter and a second center point. The first center point is coincident with the second center point and the first diameter and the second diameter are sized such that the positive semicircular proximal end fits within the negative semicircular distal end.

Abstract: A locking system comprising a block made of a polymer substance having an upper surface and a lower surface. In a normal condition, the block has the following structure. A bore, having a first axis, extends through the block and passes through the upper surface and the lower surface, the bore being shaped to include a taper, whereby an upper end of the bore has a larger diameter than a lower end of the bore, and the bore has an internal surface that is smooth. And, a slot, having a second axis, extends through the block and passes through the upper surface and the lower surface, the slot having a generally planar configuration with a width and a thickness, the slot being positioned such that the first axis and the second axis are co-axial, whereby the slot and the bore form a single continuous opening extending through the block.

Abstract: A pop-up emitter comprising a base defining a circular bore along a central axis. The base further defines a circular opening at a distal end of the bore. A hub is provided, defining an aperture, positioned in the center of the opening. A circular cap is provided, sized to fit inside the opening, the cap including a spike extending perpendicular to the cap from the center of the cap. The spike resides movably within the aperture such that the cap is movable between a closed condition in which the opening is closed, and an open condition in which the opening is open.

Abstract: A locking system comprising a block made of a polymer substance having an upper surface and a lower surface. In a normal condition, the block has the following structure. A bore, having a first axis, extends through the block and passes through the upper surface and the lower surface, the bore being shaped to include a taper, whereby an upper end of the bore has a larger diameter than a lower end of the bore, and the bore has an internal surface that is smooth. And, a slot, having a second axis, extends through the block and passes through the upper surface and the lower surface, the slot having a generally planar configuration with a width and a thickness, the slot being positioned such that the first axis and the second axis are co-axial, whereby the slot and the bore form a single continuous opening extending through the block.