A roller apparatus (102) is provided including roller means (104), drive means (110) for driving rotation of the roller means in use, and an electrical power source for providing electrical power to the drive means in use. The electrical power source is provided by one or more batteries (112) located internally of the roller means.

A roller apparatus (102) is provided including roller means (104), drive means (110) for driving rotation of the roller means in use, and an electrical power source for providing electrical power to the drive means in use. The electrical power source is provided by one or more batteries (112) located internally of the roller means.

A device for covering a surface includes a cover (9), a drum mounted to rotate and able to wind or unwind the cover, and a translation system. The translation system includes a pair of closing spools (11r) mounted to rotate about a closing shaft (12) and each coupled to a closing cord (1c) to move the drum on rails (6) in a closing sense (Dc), and an axle shaft (12) coupled to the drum (2t) the rotation of which enables winding of the cover onto the drum (2t) and to move the cover on the rails in an opening sense (Do). A motor (M) connected to a driving shaft (10M) and coupled to a clutch system is configured to enable the driving shaft to actuate alternately rotation of the closing shaft (11) and the axle shaft (12).

A system for reversibly converting stadiums into multifunctional infrastructure by removing the pitch and storing it in a pit (6), the pitch having a set of trays (1) having a total length equal to the pitch in a longitudinal direction of the pit, which are moveable, self-supporting and have layers of soil, irrigation and turf; a set of transport trolleys (2) for lifting and moving each tray (1) from its position on the pitch to the pit (6); a set of retractable trellises (5) that can be unfolded on the pit (6), for the entry of each tray (1) from above the pit; an elevator system (8) inside the pit (6) to move each tray to its final position, in storage, or on the pitch; and a storage system (7) for storing each tray in a fixed and stable position.

Sheet of insulating plates comprising successively placed lamellae of insulating plates attached to each other at their edge side which is cross directional in relation to the longitudinal direction of the sheet of insulating plates, alternately at the upper corners and lower corners of the cross directional edge sides, whereby thus formed uniform sheet of insulating plates comprising several lamellae of insulating plates can be folded into accordion-like folded stack of lamellae of insulating plates and unfolded again into a uniform sheet of insulating plates, which sheet of insulating plates has an upper surface and a lower surface. The upper surface of the sheet of insulating plates comprises a surface layer which is arranged in the longitudinal direction of the sheet of insulating plates alternately attached to and detached from the lamellae of the insulating plates in groups of two successive lamellae of insulating plates.

Sheet of insulating plates comprising successively placed lamellae of insulating plates attached to each other at their edge side which is cross directional in relation to the longitudinal direction of the sheet of insulating plates, alternately at the upper corners and lower corners of the cross directional edge sides, whereby thus formed uniform sheet of insulating plates comprising several lamellae of insulating plates can be folded into accordion-like folded stack of lamellae of insulating plates and unfolded again into a uniform sheet of insulating plates, which sheet of insulating plates has an upper surface and a lower surface. The upper surface of the sheet of insulating plates comprises a surface layer which is arranged in the longitudinal direction of the sheet of insulating plates alternately attached to and detached from the lamellae of the insulating plates in groups of two successive lamellae of insulating plates.

Novel and advantageous portable pitching lanes for softball are disclosed. In one embodiment, a pitching lane for softball is disclosed comprising a foundation layer, a surface layer, and a pitching rubber. The portable pitching lane is movable from place to place when not in use, but does not move when in use.

Novel and advantageous portable pitching lanes for softball are disclosed. In one embodiment, a pitching lane for softball is disclosed comprising a foundation layer, a surface layer, and a pitching rubber. The portable pitching lane is movable from place to place when not in use, but does not move when in use.