Patent ID: 8702369
Filing Date: 2014-04-22
Classification: B66C

Abstract:
1. A load handling system, comprising: a load movement assembly movable between a raised position and a lowered position; a load holding member connected to the load movement assembly and controllable to hold a load and to release the load; a lift cylinder operatively connected to the load movement assembly and movable to raise and lower the load; a release control member operatively connected to the load holding member to control release of the load; a load movement assembly control device movable between a first load movement assembly control device position wherein the load movement assembly control device connects the lift cylinder to a source of fluid at a first pressure, and a second load movement assembly control device position wherein the load movement assembly control device connects the lift cylinder to a source of fluid at a second pressure, wherein the first pressure is selectable so that the lift cylinder at least partially supports the weight of the load movement assembly and the load, wherein the second pressure is less than the first pressure and is selectable to be sufficient for the lift cylinder to at least partially support the weight of load movement assembly without the load and is insufficient for the lift cylinder to support the weight of the load movement assembly with the load; and a load sensing device including a housing having a first port and a second port, and a piston movable between the first and second ports, wherein the first port is fluidly connectable to the lift cylinder, wherein the second port is fluidly connectable to a source of fluid at a third pressure, wherein the piston is operatively connected to the release control member, and wherein when the lift cylinder is at the second pressure the piston is driven to a first piston position which permits the release control member to be actuated to release the load, and wherein when the lift cylinder is at the first pressure the piston is driven to a second piston position which prevents the release control member to be actuated to release the load.