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A lift boom assembly including a pair of laterally spaced interconnected lift arms having a tool mounted between forward ends thereof. Each lift arm includes a main lift link having upper and lower connecting portions at a rear end thereof. A second lift link is pivotally connected to the upper conn

A lift boom assembly including a pair of laterally spaced interconnected lift arms having a tool mounted between forward ends thereof. Each lift arm includes a main lift link having upper and lower connecting portions at a rear end thereof. A second lift link is pivotally connected to the upper connecting portion of the main lift link and partially controls movements of the respective lift arm. The opposite end of each second lift link is pivotally connected to a frame of a machine on which the lift assembly is mounted. Movement of the lift arms is further controlled by a pair of control arms. A lower end of each control arm is pivotally connected to the frame. When the boom assembly is in a lowered position relative to the frame, a second or upper end of each control arm extends upwardly and rearwardly from the lower end and is pivotally connected to the lower connecting portion of the respective main lift link. In response to vertical movements of the boom assembly between raised and lowered position, each control arm swings forwardly and rearwardly of its true vertical position to alter the movements of the lift arms and such that the tool is elevationally moved along a generally linear vertical path. A pair of extendable and retractable drivers provide powered vertical movements to the lift assembly and the tool carried thereby relative to the frame.

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A lift boom assembly mounted on a machine having a fore-and-aft extending frame, comprising: a pair of generally vertical supports for supporting the boom assembly, said supports being disposed toward a rear of the frame; a lift assembly having a pair of lift arms arranged on opposite lateral sides

A lift boom assembly mounted on a machine having a fore-and-aft extending frame, comprising: a pair of generally vertical supports for supporting the boom assembly, said supports being disposed toward a rear of the frame; a lift assembly having a pair of lift arms arranged on opposite lateral sides of the frame, each lift arm having a forward end to which a working tool is mounted and comprises a main lift link and a second lift link pivotally connected to each other, said main lift link extending rearwardly from a forward portion of the frame and including at a rear end thereof upper and lower connecting portions, said second lift link being substantially shorter in length than said main lift link and has a first end pivotally connected to the upper connecting portion of the main lift link and a second end pivotally connected to one of said supports; a pair of extendable and retractable drivers arranged on opposite sides of the frame and connected between the frame and a respective lift arm for effecting powered vertical movements of the lift assembly and the tool carried thereby relative to the frame; and a pair of control arms, each control arm having a first end pivotally connected to the frame adjacent the rear end thereof beneath the location whereat the second lift link is connected to the frame and having a second end which, when the boom assembly is in a lowered position, extends upwardly and rearwardly from the first end and is pivotally connected to said lower connecting portion of a respective main lift link.