Patent ID: 6267200
Filing Date: 2001-07-31
Classification: B66C,B66F

Abstract:
A lift apparatus for moving an arm structure, comprising:a first arm structure;a second arm structure having a first longitudinal axis, said second arm structure being rotatable relative to said first arm structure;a moving device for applying a force along a second longitudinal axis;at least one link displacing said moving device relative to said first arm structure and said second arm structure in response to and during at least a portion of a range of motion of said second arm structure for increasing said range of motion of said second arm structure relative to said first arm structure and for providing said moving device with an increased mechanical advantage for moving said second arm structure relative to said first arm structure, said displacing link being associated with said first arm structure and displacing said moving device with respect to said first arm structure during only a portion of said range of motion of said second arm structure; anda connecting portion associated with said first arm structure, said second arm structure being rotatably attached to said connecting portion, wherein said connecting portion is a connecting plate associated with said first arm structure, said second arm structure and said displacing link are connected to said connecting plate at first and second pivot points, respectively, and said first and second pivot points and a predetermined point on a longitudinal axis of said first arm structure are in a substantially triangular configuration, wherein said connecting plate includes a first attachment portion connected to said first arm structure and a second attachment portion which includes said first and second pivot points.