Abstract: An attachment for a weight stack type exercise machine to pull the weight stack down while it is being lowered, (or to pull on a weight stack lifting means so as to add to the force applied to the lifting means by the weight stack) so that the eccentric exercise force required to lower the stack is greater than the concentric exercise force required to raise it. Such asymmetric exercise forces more closely match muscle strengths, which are normally greater for eccentric exercise than for concentric exercise. The attachment has an electric motor and a control unit including a keypad, a display and a microcontroller. The motor is coupled to the weight stack by an eccentric force control cable or a toothed belt or alternatively is operatively connected so as to apply additional force to the lifting arrangement. The keypad allows the user to select the amount of force added during the eccentric phase of exercise, when the weight stack is moving down.

Abstract: An attachment for a weight stack type exercise machine to pull the weight stack down while it is being lowered, so that the eccentric exercise force required to lower the stack is greater than the concentric exercise force required to raise it. Such asymmetric exercise forces more closely match muscle strengths, which are normally greater for eccentric exercise than for concentric exercise. The attachment has an electric motor and a control unit including a keypad, a display and a microcontroller. The motor is coupled to the weight stack by an eccentric force control cable. The keypad allows the user to select the amount of force added during the eccentric phase of exercise, when the weight stack is moving down and part of a lifting cable connected to a handle or engageable member on the weight stack type machine is moving in. A sensor enables the controller to determine whether the weight stack is moving up or down.

Abstract: A motor-driven treadmill includes a stationary ultrasonic range finder which continuously measures the distance to the torso of a person walking or running on the moving tread of the treadmill. When the person approaches too closely to the front of the treadmill, the treadmill speed and/or the treadmill slope are increased; and when the person retreats too far away from the front of the treadmill, the treadmill speed and/or the treadmill slope are decreased. The response of the treadmill speed and/or slope control system may be improved by making the controller responsive to the rate of change of the distance between the person using the treadmill and the front of the treadmill, so as to provide anticipation of the distances which will be traversed by the user of the treadmill.

Abstract: A master (virtual) clock is situated at a central data gathering station, and slave (physical) clocks are situated at one or more (functionally or spatially) remote stations. Time signals are exchanged between the master clock at the central station and each slave clock at each corresponding remote station. From these signals (i) the ratio between the frequencies of the central station master clock and the corresponding remote station slave clock is determined, (ii) the difference in reference (starting) time value between the central station master clock and the corresponding remote station slave clock is determined, and (iii) the transmission time between the central station master clock and the corresponding remote station slave clock is determined. Averages of the clock ratio, reference time, and transmission time are determined across successive time signals to provide improved accuracy.

Abstract: A master clock is situated at a central data gathering station, and slave clocks are situated at one or more (functionally or spatially) remote stations. Time signals are exchanged between the master clock at the central station and each slave clock at the corresponding remote station. From these signals (i) the transmission time between the central station and the corresponding remote station is determined, and (ii) the ratio between the frequencies of the central station master clock and the corresponding remote station slave clock is determined. The transmission time and clock ratio so determined are averaged between successive determinations to provide improved accuracy. The transmission time value is used to set the slave clock to a reference value accurately corresponding to the time kept by the master clock; and thereafter the clock ratio value is used to insure that the slave clock is incremented at a rate corresponding to the frequency of the oscillator in the master clock.