Lift boom assembly

A lift boom assembly movable between lowered and raised positions and adapted for use on a work machine having a longitudinal centerline, a frame with front and rear end portions and upper and lower portions with the front and rear end portions including respective front and rear drive axes, comprising:

• a pair of supports connectable to the rear end portion of the frame for supporting the lift boom assembly;
• a pair of lift arm assemblies positionable on opposite sides of the longitudinal centerline and pivotally connected to a respective support, each of the lift arm assemblies including a main lift link with front and rear end portions and a second lift link, the second lift links each having a first end portion, a second end portion pivotally connected to a respective one of the supports, and a central portion located between the first and second end portions and pivotally connected to the rear end portion of a respective main lift link;
• a pair of extendible and retractable hydraulic actuators disposable on opposite sides of the longitudinal centerline and connected between the frame and a respective lift arm assembly for moving the lift boom assembly between the lowered and raised positions;
• and
• a pair of control links with each having first and second end portions, the first end portion of each of the control links being pivotally connected to a respective one of the supports and the second end portion of each of the control links being pivotally connected to a respective one of the main lift links, the second end portion of the control links extending downwardly and rearwardly from the first end portion of the control links when the lift boom assembly is in the lowered position and upwardly and rearwardly from the first end portion of the control links when the lift boom assembly is in the raised position.

A work machine having a longitudinal centerline, a frame with front and rear end portions and upper and lower portions with the front and rear end portions including respective front and rear drive axes, comprising:

• a pair of supports connected to the rear end portion of the frame for supporting the lift boom assembly;
• a pair of lift arm assemblies positioned on opposite sides of the longitudinal centerline and pivotally connected to a respective support, each of the lift arm assemblies including a main lift link with front and rear end portions, a mounting brace located beneath and extending from each of the main lift links and located between the front and rear end portions of each of the main lift links, and a second lift link, the second lift links each having a first end portion, a second end portion pivotally connected to a respective one of the supports to define a first pivot, and a central portion located between the first and second end portions and pivotally connected to the rear end portion of a respective main lift link to define a second pivot;
• a pair of extendible and retractable hydraulic actuators disposed on opposite sides of the longitudinal centerline and connectable between the frame and a respective lift arm assembly for moving the lift boom assembly between the lowered and raised positions;
• and
• a pair of control links with each having first and second end portions, the first end portion of each of the control links being pivotally connected to a respective one of the supports to define a third pivot and the second end portion of each of the control links being pivotally connected to a respective one of the mounting braces to define a fourth pivot with each of the first, second, third, and fourth pivots being located above the lower portion of the frame at a vertical height that is at least one-half of the height of the work machine or greater.

A lift boom assembly movable between lowered and raised positions and adapted for use on a work machine having a longitudinal centerline, a frame with front and rear end portions and upper and lower portions, comprising:

• a support connectable to the rear end portion of the frame for supporting the lift boom assembly;
• a lift arm assembly pivotally connected to the support, the lift arm assembly including a main lift link with front and rear end portions and a second lift link, the second lift link having a first end portion, a second end portion pivotally connected to the support to define a first pivot, and a central portion located between the first and second end portions and pivotally connected to the rear end portion of the main lift link to define a second pivot;
• an extendible and retractable actuator connectable between the frame and the lift arm assembly for moving the lift boom assembly between the lowered and raised positions;
• and
• a control link having first and second end portions, the first end portion of the control link being pivotally connected to the support to define a third pivot and the second end portion of the control link being pivotally connected to the main lift link to define a fourth pivot with each of the first, second, third, and fourth pivots being located above the lower portion of the frame at a vertical height that is at least one-half of the height of the work machine or greater.

A lift boom assembly movable between lowered and raised positions and adapted for use on a work machine, a frame with front and rear end portions and upper and lower portions, comprising:

• a support connectable to the rear end portion of the frame for supporting the lift boom assembly;
• a lift arm assembly pivotally connected to the support, the lift arm assembly including a main lift link with front and rear end portions and a second lift link, the second lift link having a first end portion, a second end portion pivotally connected to the support, and a central portion located between the first and second end portions and pivotally connected to the rear end portion of the main lift link;
• an extendible and retractable actuator connected between the frame and the lift arm assembly for moving the lift boom assembly between the lowered and raised positions;
• and
• a control link having first and second end portions, the first end portion of the control link being pivotally connected to the support and the second end portion of the control link being pivotally connected to the main lift link, the second end portion of the control link extending downwardly and rearwardly from the first end portion of the control link when the lift boom assembly is in the lowered position and upwardly and rearwardly from the first end portion of the control link when the lift boom assembly is in the raised position.

A lift boom assembly movable between lowered and raised positions and adapted for use on a work machine having a longitudinal centerline, a frame with front and rear end portions and upper and lower portions, comprising:

• a lift arm assembly pivotally connectable with the frame, the lift arm assembly including a main lift link and a second lift link, the second lift link being pivotally connectable with the frame to define a first pivot and pivotally connected to the main lift link to define a second pivot;
• an actuator connectable between the frame and the lift arm assembly for moving the lift boom assembly between the lowered and raised positions;
• and
• a control link being pivotally connectable with the frame to define a third pivot and being pivotally connected to the main lift link to define a fourth pivot with the third and fourth pivot being located vertically between the first and second pivot throughout movement from the lowered position to the raised position and each of the first, second, third, and fourth pivots being located above the lower portion of the frame at a vertical height that is at least one-half of the height of the work machine or greater.