A game-court-surface projector system and method providing projection of a variety of projected images upon a game court or half court, showing proper boundaries and lines for various games and levels of play, allowing multiple uses for one game court or half court, allowing the development of new games or variants, and allowing improved training and practice by using accurate boundaries and lines for different games and levels of play, and using other projected images.

A plot measurement system which enables a user to singlehandedly mark boundaries and features of a sports field or construction site with improved accuracy. The system utilizes a plurality of vertex markers connected by measuring leaders to provide triangulation. A three-vertex marker system can be used to construct triangles, which can then be used to construct any n-sided shape. The concept is scalable and a four-vertex marker system is presented to quickly construct quadrangle plots such as an endzone. The disclosure presents mechanical and electrical systems.

A method of installing a binder-based overlay system may include contacting a layer of geotextile fabric to a surface of a substrate and applying a primer layer to a surface of the geotextile fabric. Two or more binder layers including infill particles may be applied over the primer layer. A resurfacer layer followed by one or more color layers may be applied over the two or more binder layers. The primer layer, one or more binder layers, resurfacer layer, and two or more color layers may cure upon application to form a monolithic layer upon the substrate.

A ground marking apparatus is configured to apply marking material to a ground surface. The ground marking apparatus includes a beam supported by a beam mount and extending along a beam axis. A carriage is disposed on the beam and movable on the beam along the beam axis. A carriage motor operably interfaces with the beam and is configured to move the carriage along the beam. A dispense arm is supported by the carriage and is configured to move relative to the beam as the carriage moves along the beam.

Systems and devices for a team game played on an obround court includes radially symmetric barriers defining cylindrical goals having circular openings concentric with the semicircles of the obround court. An annular halt zone extends around the barriers. A free throw line extends around each halt zone. An obround judge lane extends along the perimeter of the court and is occupied by two judges or referees that monitor the game, while another judge or referee remains inside the perimeter. The court is divided by a centerline which includes a circle at the center of the court. The outer wall of the barrier includes one or more video screens. Audience members can access a computer network to display images, text or video selected by them in real-time during gameplay. The ball used for the game has a surface texture provided by a plurality of square pebbles instead of rounded pebbles.

A play surface marking system may include a first fabric strip configured to be attached to a play surface using a first adhesive strip and a second adhesive strip, wherein the first fabric strip defines a first boundary on the play surface and a second fabric strip configured to be attached to the play surface using a third adhesive strip and a fourth adhesive strip, wherein the second fabric strip defines a second boundary on the play surface.

A display device for showing a court line is provided. The court line is adapted to be shown on an indoor field. The display device includes field line sets disposed on a predetermined field. The field line sets have marker lines, and two or more of the marker lines overlap with each other. Each marker line includes a thin transparent body. The thin transparent body includes a protective film, a conductive layer, a light-emitting layer, an insulating layer, and an electrode layer. The light-emitting layer is made of a material including an electrochromic material. Each marker line in each field line set has an independent circuit loop. Thus, by energizing the light-emitting layer of the desired marker lines to make it emit light, the desired court lines will be shown correspondingly, thus avoiding the problem of causing users to be confused among multiple sets of court lines.

A ground marking autonomous robot containing a flexible bag containing a marking material therein, the flexible bag provided with an airtight valve outlet sealed to the flexible bag. The use of a ground marking autonomous robot with a flexible bag allows for improvements in the accuracy of the deposition of material, for example in image printing or fertiliser deposition. This allows the optimisation of material deposition, and material use, minimising environmental impact with no compromise to quality of finished product, e.g. a printed logo or a fertilised pitch.

A ring for a fighting sport has a circular fighting area defined by a plurality of circular fence rings that are held up by posts. Shock absorbers connect the fence rings to the posts. Position markers are provided to indicate the starting positions of the participating fighters at certain points during the bout.

Methods and apparatus are discussed for an electric powered personal transportation vehicle with electric motors powered by one or more batteries. A set of universal battery mounting hole locations and a reserved space for one or more battery housings exist on a board for the personal transportation vehicle. The reserved space on the board for the one or more battery housings that house one or more battery packs is set to not interfere with an operation of the motors or the wheels. A first battery pack containing the one or more batteries differs in at least one of i) a different amp-hour capacity, ii) a different length, width, or height, and iii) a different shape than another battery pack designed to be physically contained in the one or more battery housings and electrically connect with corresponding electrical connections in the one or more battery housings.