Carriage assembly and side shift system for a lift truck
AssigneeClark Material Handling Company
InventorsClark C. Simpson, Jeffrey C. Hansell, Jack L. Shafe
Life of this patent
Estimating the term…
Abstract
A carriage assembly, 20h for a lift truck upright assembly, 12, has pivotally mounted forks, 30, controlled by hydraulic cylinders, 36, that are operated by side shifter circuit, 110, having a single operator control, 124, for manipulating the forks in unison, opening or closing the forks, or shifting them right or left in a coordinated fashion.
Claims11
An upright assembly for a counterbalanced lift truck having a front chassis portion adapted for carrying said upright assembly and a rear chassis portion adapted for carrying a counterweight for counterbalancing a load to be lifted on said upright assembly comprising;
- pivotal mounting means on the upright assembly cooperating with said front chassis portion of the truck to allow the upright assembly to tilt forward or backward from a vertical plane;
- cylinder means extending between the lift truck and upright assembly for tilting it on said pivotal mounting means;
- a pair of forks spaced laterally apart adapted for movement up and down on the upright assembly in raising or lowering a load, each fork having a horizontal load carrying portion and a vertical leg portion secured to the horizontal load carrying portion;
- fork mounting means supported on the upright assembly for movement thereon, each fork being suspended thereon from said vertical leg portion and pivoting on an axis substantially parallel to, and vertically above, said horizontal load carrying portion in a primary load engagement position of said pair of forks;
- cylinder means connected to said fork mounting means for moving it up and down the upright assembly;
- fork actuator means on the fork assembly means causing one or both of said forks to pivot on its axis to one side or the other on each fork outwardly from its primary load engagement position;
- strut means cooperating between each said vertical leg portion and fork mounting means along a path extending laterally wider than the primary load engagement position establishing a bearing surface extending outwardly therefrom for lifting loads wider than fork spacing in the primary load engagement position.
An upright assembly for a lift truck having drive and steerable wheels on which the lift truck and upright assembly travel in lifting, maneuvering and transporting loads comprising;
- a carriage assembly supported for a movement up and down said upright assembly in a direction upwardly above the wheels in a positive lift mode and in a direction below the wheels in a negative lift mode;
- a pair of forks, spaced apart on the carriage assembly approximately the width of the upright assembly, each fork having a horizontal blade portion for engaging a load to be lifted and a vertical rear leg portion secured to the blade portion;
- said carriage assembly including upper and lower horizontal fork bars extending substantially the width of said upright assembly behind said rear leg portions of the forks;
- pivotal mounting means on the upper fork bar to which said rear leg portions are mounted from which the forks are pivoted;
- actuator means mounted on said carriage assembly connected to each fork for pivoting both forks in one direction, or each fork toward or away from the other;
- and
- bearing means connected to each fork projecting laterally in overlapping relationship with said lower fork bar for maintaining engagement therewith when either of said forks is pivoted wider than the upright assembly to accommodate oversized loads whereby the carriage assembly may be lowered from in the negative lift mode with the forks spread wider than the upright assembly and thereafter the forks are pivoted inwardly for engaging the load from above.
Dependencies are inferred from the claim text.