Abstract: A measurement system for evaluating athletes using a weighted resistance towing sled to which an athlete is connected using a harness and tether, is described, the measurement device comprising: a force sensing device located in the connection between the athlete and the sled, the force sensing device having a load cell, the force sensing device measuring the force exerted on the sled by the athlete; a second sensing device, the second sensing device having at least one accelerometer; and a communication device for communicating data from the sensing devices, wherein the second sensing device provides data for the calculation of at least linear velocity, linear acceleration and linear distance travelled.

Abstract: A threaded follower mounted on a spiral rod is attached to the first end of a torsion spring, the second end of the torsion spring being connected to a window sash, one end of the spiral rod being attached to a window frame by a gear box that prevents rotation of the spiral rod unless the gear box receives externally provided rotational force by which it then rotates the spiral rod.

Abstract: A threaded follower mounted on a spiral rod is attached to the first end of a torsion spring, the second end of the torsion spring being connected to a window sash, one end of the spiral rod being attached to a window frame by a gear box that prevents rotation of the spiral rod unless the gear box receives externally provided rotational force by which it then rotates the spiral rod.