Patent ID: 6799749
Filing Date: 2004-10-05
Classification: B66F

Abstract:
A pantograph jack comprising, in combination:a base; a load rest; first and second lower arms each pivotably coupled at a first end thereof to the base; first and second upper arms each pivotably coupled at a first end thereof to the load rest; wherein second ends of the first lower arm and the first upper arm are pivotably coupled at a first joint; wherein second ends of the second lower arm and the second upper arm are pivotably coupled at a second joint; wherein the first and second joints are disposed on a substantially horizontal diagonal of a parallelogram formed by the first and second lower arms and the first and second upper arms; a drive screw extending between the first and second joints and operably moving the first and second joints toward and away from each other upon rotation of the drive screw about a longitudinal axis of the drive screw coaxial with the diagonal; a bearing support forming a bearing engagement surface along the central axis and outwardly spaced from the second lower arm and the second upper arm; wherein the bearing engagement surface has a lateral width greater than a lateral width of at least one of the second lower arm and the second upper arm; wherein the drive screw has an abutment facing the bearing engagement surface; a bearing having an opening coaxial with the drive screw and receiving the drive screw therethrough; and wherein the bearing located between the bearing engagement surface and the abutment.