Patent ID: 7637709

Claim:
A mechanical manipulator comprising: a support frame comprising: a front surface; a lateral surface perpendicular to the front surface; a vertical track that extends in a vertical direction; and a plurality of holes in the front surface; a lift component secured to the support frame for applying a lifting force in the vertical direction; a load supporting component operably connected to the vertical track for movement in the vertical direction; a rotatable lever operably connected to the lift component and to the load supporting component, the rotatable lever being biased in a first rotational direction, and being configured to rotate in a second rotational direction, opposite of the first rotational direction, in response to the lifting force applied by the lift component; a biasing component operably connected to the rotatable lever for applying a biasing force to bias the rotatable lever in the first rotational direction; and a locking component operably connected to the rotatable lever, and being configured to engage the holes of the support frame when the rotatable lever rotates in the first rotational direction in response to a downward force on the load supporting component that exceeds the lifting force.