Travel and fork lowering speed control based on fork load weight/tilt cylinder operation

摘要

A fork lift truck includes a body, a drive mechanism supported on the body for effecting movement of the body, and a fork carrying assembly carrying forks which can be moved in height between a lowered position and desired raised positions. A tilt cylinder is provided for tilting the forks through a fork tilt range. The truck further includes a pressure sensor capable of generating signals indicative of the weight of a load on the forks, a fork tilt position sensor capable of being activated when the forks are tilted to extremes of the fork tilt range, and a controller. The controller is coupled to the drive mechanism, the pressure sensor and the fork tilt position sensor. It causes the drive mechanism to effect movement of the body up to a first maximum speed when at least one of the pressure sensor generates a signal indicative of a load on the forks having a weight above a predetermined value and the tilt position sensor is activated, and causes the drive mechanism to effect movement of the body up to a second maximum speed which is greater than the first maximum speed when the pressure sensor generates a signal indicative of no load or a load on the forks having a weight below the predetermined value and the tilt position sensor is inactivated. The lowering speed of the forks can also or alternatively be increased under the same operating conditions.