Abstract: Within a counteracting block and tackle system of compact arrow launching devices, a cable-suspended, moveable pulley block structure permits the through clearance of razor-edged arrow broadheads and employs a plurality of low-density, solid sheaves, aligned in series to guide the in-line purchase of bowstring. The moveable pulley block has a hollow-though structure that permits the radial clearance of an arrow broadhead, reducing potential external interference or contact with the razor edges of the broadhead. The pulley block is attached to cable terminals at one end which allow the pulley block to travel in cooperating with cables. The pulley block has low-density, solid sheaves that facilitate high velocity launching cord travel with low rotational momentum for reduced friction and wear. The sheaves and cable terminals, and any launching cord terminals, are aligned in series and share a single linear plane to minimize launching cord fleet angles, reduce friction and increase efficiency.

Abstract: An elastic energy storage and deployment system deploys a torsional spring that bias a cam connected to a cable. The cam is coupled to the torsion spring about a shared rotational axis such that the cam directs elastic energy to and from the torsion spring and the cable transforms rotational force into linear motion, with little rotational inertia, and the addition of angular acceleration.

Abstract: A tension management system employs moveable anchors, tension pins, ports and tuning string within torsion spring and cam elastic energy storage and deployment counteracting block and tackle systems. In conjunction with prescribed methods, launching cords and cables can be installed and replaced in field conditions, with precise tension for dynamic balance, without the need for bulky and expensive external presses.

Abstract: An elastic energy storage and deployment system deploys a torsional spring that bias a cam connected to a cable. The cam is coupled to the torsion spring about a shared rotational axis such that the cam directs elastic energy to and from the torsion spring and the cable transforms rotational force into linear motion, with little rotational inertia, and the addition of angular acceleration.

Abstract: An elastic energy storage and deployment system deploys a torsional spring that bias a cam connected to a cable. The cam is coupled to the torsion spring about a shared rotational axis such that the cam directs elastic energy to and from the torsion spring and the cable transforms rotational force into linear motion, with little rotational inertia, and the addition of angular acceleration.

Abstract: An elastic projectile propulsion system deploys a plurality of springs that bias a common launching cord via a plurality of block and tackle pulleys. Each sheave of the pulley is coupled to the moveable end of a spring such that the force of each spring contributes to the energy imparted to a projectile by the launching cord without adding significant friction or inertial resistance.

Abstract: An elastic projectile propulsion system deploys a plurality of springs that bias a common launching cord via a plurality of block and tackle pulleys. Each sheave of the pulley is coupled to the moveable end of a spring such that the force of each spring contributes to the energy imparted to a projectile by the launching cord without adding significant friction or inertial resistance.