An industrial truck includes a vehicle frame and a drive unit. The drive unit includes a drive wheel movably mounted to the vehicle frame and a spring unit. The spring unit includes a hydraulic cylinder positioned between the vehicle frame and the drive unit and a switchable valve configured to define a blocked state. The spring unit is configured to pretension the drive wheel against a ground surface. When the switchable valve is in the blocked state, a one-sided movement of the hydraulic cylinder is blocked.

A wheel assembly includes a wheel having an axle, and a constant force mechanism coupled to the wheel. The constant force mechanism includes a horizontal support, a horizontal carriage associated with the horizontal support, a vertical support oriented perpendicular with respect to the horizontal support, a vertical carriage associated with the vertical support, and a rigid arm that is pivotally coupled with the horizontal carriage, the vertical carriage, and the axle. The rigid arm is coupled with the vertical carriage at a point intermediate where the rigid arm is coupled with the horizontal carriage and the axle. The horizontal carriage is capable of being urged along the horizontal support, and the vertical carriage is capable of being urged along the vertical support.

A support roller (30, 30′) for supporting a vehicle on an underlying surface, comprising at least one bearing element which is at least indirectly connectable to at least one supporting structure of the vehicle, at least one fork connected to the bearing element, and at least one wheel (90, 90′) which is mounted in the fork so as to be rotatable about a first rolling axis (R) and can be brought into contact with the underlying surface, at least one sensing device (190 ) for sensing at least one supporting force with which the wheel (90, 90′) is supported on the underlying surface. A vehicle, in particular an industrial truck, comprising at least one support roller and a method for stabilizing a vehicle.

A support roller (30, 30′) for supporting a vehicle on an underlying surface, comprising at least one bearing element which is at least indirectly connectable to at least one supporting structure of the vehicle, at least one fork connected to the bearing element, and at least one wheel (90, 90′) which is mounted in the fork so as to be rotatable about a first rolling axis (R) and can be brought into contact with the underlying surface, at least one sensing device (190) for sensing at least one supporting force with which the wheel (90, 90′) is supported on the underlying surface. A vehicle, in particular an industrial truck, comprising at least one support roller and a method for stabilizing a vehicle.

A support roller (30, 30) for supporting a vehicle on an underlying surface, comprising at least one bearing element which is at least indirectly connectable to at least one supporting structure of the vehicle, at least one fork connected to the bearing element, and at least one wheel (90, 90) which is mounted in the fork so as to be rotatable about a first rolling axis (R) and can be brought into contact with the underlying surface, at least one sensing device (190) for sensing at least one supporting force with which the wheel (90, 90) is supported on the underlying surface. A vehicle, in particular an industrial truck, comprising at least one support roller and a method for stabilizing a vehicle.

A wheel assembly includes a wheel having an axle, and a constant force mechanism coupled to the wheel. The constant force mechanism includes a horizontal support, a horizontal carriage associated with the horizontal support, a vertical support oriented perpendicular with respect to the horizontal support, a vertical carriage associated with the vertical support, and a rigid arm that is pivotally coupled with the horizontal carriage, the vertical carriage, and the axle. The rigid arm is coupled with the vertical carriage at a point intermediate where the rigid arm is coupled with the horizontal carriage and the axle. The horizontal carriage is capable of being urged along the horizontal support, and the vertical carriage is capable of being urged along the vertical support.

A support roller (30, 30) for supporting a vehicle on an underlying surface, comprising at least one bearing element which is at least indirectly connectable to at least one supporting structure of the vehicle, at least one fork connected to the bearing element, and at least one wheel (90, 90) which is mounted in the fork so as to be rotatable about a first rolling axis (R) and can be brought into contact with the underlying surface, at least one sensing device (190 ) for sensing at least one supporting force with which the wheel (90, 90) is supported on the underlying surface. A vehicle, in particular an industrial truck, comprising at least one support roller and a method for stabilizing a vehicle.

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.

A load transporting apparatus is described including: a main body; a ground engaging wheel positioned at or towards one end of the main body and supported for rotation about a generally horizontal axis; a support member, which is connected to the main body, and which supports a pair of wheel assemblies, each assembly including a wheel which is supported for rotation about a generally horizontal wheel axis, wherein said wheel assembly permits the wheel to swivel about a swivel axis which is substantially perpendicular to the wheel axis and off-set therefrom; wherein the support member is connected to the main body by connection means which permits movement of the main body towards and away from the support member. Also described is an apparatus where the or a further connection means is configured to permit rotation of the support member relative to the main body about an axis which extends generally in a fore-aft direction of the apparatus.

An industrial truck includes a vehicle frame and a drive unit. The drive unit includes a drive wheel movably mounted to the vehicle frame and a spring unit. The spring unit includes a hydraulic cylinder positioned between the vehicle frame and the drive unit and a switchable valve configured to define a blocked state. The spring unit is configured to pretension the drive wheel against a ground surface. When the switchable valve is in the blocked state, a one-sided movement of the hydraulic cylinder is blocked.