Spring balance assembly

Abstract

This invention provides for a loading arm for use with material handling systems and includes a support structure and an arm pivotally attached to the support structure for swivel movement in both the horizontal and vertical plane relative to the support structure. There is also provided a balancing system for balancing the swivel arm relative to the support structure which includes a coil spring having a pre-determined length, a housing enclosing the coil spring, a first end of the housing having a structure for engaging a first coil end of the coil spring and an adjustment device for positioning that first coil end in infinitely small increments along a generally circular path which is radially disposed from the center line of the spring, a second end of the housing having another groove for engaging a second coil end of the spring, a linkage arm attached at one end to the swivel arm and at its other end to the second end such that movement of the swivel arm in the vertical plane will cause the second coil end to move along a generally circular path radially disposed from the centerline of the spring. The system also includes a mounting structure for attaching the balancing system to the loading arm and the horizontal swivel.