1. A device for use in preventing overloading of a load lift device of the type having an electric circuit for controlling load lifting operations, which comprises in combination: a pair of members; means for coupling said members for relative movement initially within a first range of movement when said lift device is subject to relatively low loadings and then within a second range of movement when said lift device is subject to relatively high loadings including an overload to be prevented, said coupling means tending to constrain said members from relative movement for loadings intermediate about said relatively low and relatively high loadings; and switch means for controlling said circuit, said switch means having a movable actuator and characterized as having cir-cuit cutout and circuit reset conditions Occurring at different points along the path of actuator travel, said switch means being associated with said members whereby to produce travel of said actuator upon relative movement of said members and to place said switch means in said cutout condition upon occurrence of said overload during relative movement of said members within said second range of movement and in said reset condition upon reduction of lift device loading permitting relative movement of said members in said first range of movement.

4. A device for use in preventing overloading of a load lift device of the type having an electric circuit for controlling load lifting operations, said lift device being characterized as having a rated load while being capable of lifting without failure loads up to an overload which is greater than said rated load and of experiencing without failure impact/acceleration forces produced rated load oscillations within a range bounded by an upper loading corresponding to said overload and a lower loading less than said rated load, which comprises in combination: a pair of members; means for coupling said members for relative movement initially within a first range of movement when said lift device is subject to relatively low loadings below about said lower loading and then within a second range of movement when said lift device is subject to relatively high loadings intermediate about said lower loading and said overload; a switch for controlling said electric circuit, said switch having a movable actuator and being characterized as having circuit cutout and circuit reset conditions occurring at different points along the path of actuator travel; and an operator for controlling movement of said switch actuator, said switch and said operator being fixed relative one to each of said members whereby to produce travel of said actuator by engagement with said operator upon relative movement of said members and to place said switch in said cutout condition upon occurrence of said overload during relative movement of said members within said second range of movement and in said reset condition upon reduction of lift device loading permitting relative movement of said members in said first range of movement.

7. A device for use in suspending a hoist from a support and for preventing overloading of said hoist, said hoist having an electrical circuit for controlling load lifting operations, said device comprising in combination: a first member connectable to said support; a second member connectable to said hoist, said first member having a bottom wall apertured to receive said second member for vertical rEciprocating movement relative thereto; and an assembly for coupling said members for relative movement during load lifting operations and for controlling said electrical circuit, said assembly including preload means fixed to said second member, a sleeve member disposed above said bottom wall and about said second member, a first compression spring means and engaged by said sleeve member and said bottom wall and tending to bias said sleeve member upwardly away from engagement with said bottom wall, other means fixed for movement with said second member at a point vertically above said preload means, a second spring means and engaged between said sleeve member and said other means and tending to bias said sleeve member into engagement with said preload means, a switch having a movable actuator and being characterized as having circuit cutout and circuit reset conditions occurring at different points along the path of actuator travel, and an operator, said first spring means being deformable under relatively low hoist loadings thereby to permit initial downward movement of said second member relative to said first member within a first range of movement limited by engagement of said sleeve member with said bottom wall, and said second spring means being deformable only under relatively high hoist loadings including an overload thereby to permit further downward movement of said second member relative to said first member within a second range of movement, said switch and said operator being fixed relative one to each of said first and second members whereby upon relative movement of said members said operator effects movement of said actuator along said path of travel to place said switch means in said cutout condition upon occurrence of said overload during said second range of movement and in said reset condition during said first range of movement.

10. A device for use in preventing overloading of a load lift device of the type having a circuit for controlling load lifting operations, which comprises in combination: a pair of relatively movable members; a first spring device deformable under relatively low lift device loadings for permitting relative movement of said members within a first range of movement; a second spring device deformable under relatively high lift device loadings including an overload to be prevented for permitting further relative movement of said members within a second range of movement; a switch fixed to one of said members for controlling said circuit, said switch having an actuator movable relative thereto and said one member, said switch being characterized as having circuit cutout and circuit reset conditions occurring at different points spaced along the path of actuator travel; and an operator fixed to another of said members for controlling movement of said actuator, said operator moving said actuator along its path of travel upon relative movement of said members whereby to place said switch in said circuit cutout condition upon occurrence of said overload during movement of said members within said second range of movement and to place said switch in said reset condition upon reduction of lift device loading permitting relative movement of said members within said first range of movement.