Lift vehicle with fail-safe overload protective system

摘要: An overload protective system continuously monitors the forward overturning moment on a counterbalanced lift truck and prevents further raising of carriage or tilting mast when is excessive. Resistance strain gage sensors mounted load carrying tilt jack pin which resists are connected in an electrical bridge may be inherently unbalanced due to weight unloaded derives signal proportional mechanical anchor supports load; high gain differential amplifier raises level output from unbalance compensating adjustment means permit selective variation potential difference between inputs until its voltage substantially zero thereby compensate for unloaded; visual indicator lighted indicate that compensated for; comparator trip reaches predetermined magnitude shift register receiving clock pulses oscillator as time reference records history decoder analyzes sets latch has been present interval time; disabling responsive setting de-energize operating coils blocking valves inhibit mast.