摘要:
A wheel assembly includes a constant force mechanism and a wheel coupled to the constant force mechanism. The wheel is displaceable in at least one dimension, and the constant force mechanism imparts a substantially constant force on the wheel in the dimension. In one aspect, the wheel is displaceable in a first regime and a second regime. For a wheel displacement in the first regime, the constant force mechanism imparts a substantially constant force on the wheel, and for a wheel displacement in the second regime, the constant force mechanism imparts a variable force on the wheel. The variable force can be linear or non-linear to the magnitude of the displacement in the second regime and is equal to or greater than the substantially constant force.
摘要:
An electric actuator replaces the hydraulic reach actuator in a reach carriage for a reach truck. The electric actuator may be a linear actuator and may have a rotary motor and a combination ball screw and ball assembly for converting the rotary motion of the motor into linear motion to extend and retract a rod. A force limiter can be disposed between the motor and the ball screw, and may be coupled to the motor and the ball screw. The force limiter prevents a contact force on the rod from damaging the motor. The force limiter allows the reach carriage to operate normally until a contact force occurs, then disengages if a threshold level of force is exceeded. The force limiter may be a torque limiter that automatically reengages after the contact force has attenuated.
摘要:
A wheel assembly includes a constant force mechanism and a wheel coupled to the constant force mechanism. The wheel is displaceable in at least one dimension, and the constant force mechanism imparts a substantially constant force on the wheel in the dimension. In one aspect, the wheel is displaceable in a first regime and a second regime. For a wheel displacement in the first regime, the constant force mechanism imparts a substantially constant force on the wheel, and for a wheel displacement in the second regime, the constant force mechanism imparts a variable force on the wheel. The variable force can be linear or non-linear to the magnitude of the displacement in the second regime and is equal to or greater than the substantially constant force.
摘要:
Systems and methods maintain a lift truck within defined bounds. A controller analyzes actual and/or predicted lift truck behavior, and based on the analyzed lift truck behavior, the controller control at least one lift truck performance parameter. The performance parameter is controlled to maintain the lift truck center of gravity within a stability map, the stability map to define a three-dimensional range of center of gravity positions that maintains lift truck stability. The performance parameter is also controlled to maintain an intended path of the lift truck within an allowable deviation map, the allowable deviation map defining a two-dimensional envelope of allowable lift truck travel deviation from the intended path of the lift truck.
摘要:
An electromagnetic brake system and brake for controlling motion between a first machine body (32) and a second machine body (34) is provided. The electromagnetic brake system and brake include an interior core member (36), the interior core member coupling with the first body (32). The electromagnetic brake includes an outer exterior member (38), the outer exterior member enclosing the interior core member, the outer exterior member coupling with the second body. The electromagnetic brake includes a resilient spring brake lock member (40) having a brake torque stiffness, the resilient spring brake lock member (40) between the interior core member (36) and the outer exterior member (38), the resilient spring brake lock member (40) engaging the interior core member (36) wherein the resilient spring brake lock member inhibits rotation between the outer exterior member and the interior core member, and an electromagnetic field applied by an electromagnetic unlocking member disengages the resilient spring brake lock member from engaging the interior core member and provides for rotation between the outer exterior member and the interior core member.
摘要:
A wheel assembly for a material handling vehicle includes a chassis, a first caster wheel mounted to the chassis, a second caster wheel mounted to the chassis, a torsion bar coupling the first caster wheel to the second caster wheel, and a constant force mechanism coupled to at least one of the first caster wheel, the second caster wheel and the torsion bar. The first and second caster wheels are displaceable in at least one dimension, and the constant force mechanism imparts a substantially constant force opposing a displacement in the at least one dimension.
摘要:
A lift truck can include a mast and a lift cylinder. The lift cylinder can include a piston rod and a cylinder housing. The lift truck also can include a piston rod retention mechanism that restricts movement of the lift cylinder in a direction lateral to an axial direction when the mast is in an extended position.
摘要:
A lift truck can include a mast and a lift cylinder. The lift cylinder can include a piston rod and a cylinder housing. The lift truck also can include a piston rod retention mechanism that restricts movement of the lift cylinder in a direction lateral to an axial direction when the mast is in an extended position.
摘要:
A wheel assembly for a material handling vehicle includes a chassis, a first caster wheel mounted to the chassis, a second caster wheel mounted to the chassis, a torsion bar coupling the first caster wheel to the second caster wheel, and a constant force mechanism coupled to at least one of the first caster wheel, the second caster wheel and the torsion bar. The first and second caster wheels are displaceable in at least one dimension, and the constant force mechanism imparts a substantially constant force opposing a displacement in the at least one dimension.
摘要:
Systems and methods maintain a lift truck within defined bounds. A controller analyzes actual and/or predicted lift truck behavior, and based on the analyzed lift truck behavior, the controller control at least one lift truck performance parameter. The performance parameter is controlled to maintain the lift truck center of gravity within a stability map, the stability map to define a three-dimensional range of center of gravity positions that maintains lift truck stability. The performance parameter is also controlled to maintain an intended path of the lift truck within an allowable deviation map, the allowable deviation map defining a two-dimensional envelope of allowable lift truck travel deviation from the intended path of the lift truck.