Force, Power and Human Operated Machines

Human Force and Power Limits

For man operated machines the force and power must be kept within certain limits.

Pedal Force Limits

• Sitting person with solid backrest: Maximum horizontal force = 1000 N
• Sitting person: Maximum vertical force = 300 N
• Standing person: Maximum vertical force = 500 N

Lever and Rotating Wheel Operation

• Vertical lever (pump): Maximum force = 90-100 N, Frequency ≤ 20 beats/min
• Rotating wheel/crank arm:
  • Arm length (radius) ≈ 0.4 m
  • Maximum force ≤ 130 N
  • Speed ≤ 25-30 rpm
  • Axle height ≈ 1 m