Mechanical hand trucks with enhanced stair climbing and descending capability

A hand truck for facilitated lifting of loads up steps of a staircase, each having a riser height, the hand truck comprising:

• a) a frame having a first end and a second end;
• b) at least one handle adjacent the first end of the frame;
• c) at least one load supporting element extending from a front of the frame, proximate the second end, and configured for supporting a load;
• d) optionally at least two wheels adjacent the second end of the frame and configured to support the frame and load supporting element for rolling movement;
• wherein the hand truck further comprises a separated levering mechanism at the back of the frame configured to be deployed to be affected by a shift of a center of gravity of the load on the hand truck, wherein, when the mechanism is subjected to a pressure of applied weight resulting from sequential shifts of the center of gravity, backward toward the handle, the hand truck is caused to move backward, thereby facilitating lifting of the hand truck up above a first riser height of a step and movement of the hand truck with supported load to a next step or supporting surface, wherein the levering mechanism comprises:
• i) an upper lever element hingedly attached to the frame proximate to its upper end and adjacent to the at least one handle;
• ii) a lower levering element proximate to its lower second end;
• and
• iii) a lifting element hingedly attached to the lower second end of the frame and the lower levering element hingedly attached thereto, whereby the lifting element is configured to sufficiently lift the lower levering element to clear an adjacent riser of the first riser height and to enable the levering element to assume a levering configuration.

A mechanical method for enhancing the capacity of a hand truck, in being able to move large capacity weight loads up stairs and controllably down stairs, when operated by a single user, the hand truck being comprised of a supporting frame with first and second ends, with a controlling handle at the first end and a load support load supporting element at a second end, the method comprising the steps of:

• a) providing a lever member having a first end pivotally connected to the first end of the frame, at a first end of the lever member with a second end of the lever member being free, wherein the free end of the lever member is configured to be positioned against a surface and the frame pivoted thereabout on the lever member, wherein the free end of the lever member comprises a movable boot member which maintains a position in line with the lever member when directly pressure engaged with a surface of a step and which is bendable and moves out of line with the lever member when it is disengaged from the surface and engaged with a riser of a step and wherein the movable boot member is deployable in line with the lever member and movable out of line with the lever member without removal of manual control of the handle by a user thereof;
• b) providing the hand truck with an engageable and disengageable intermediate weight support or position stabilizer which is configured to be deployable after initial levered lifting to permit the integral hinged lever member to be disengaged for elongation without downward movement of the hand truck, to provide subsequent additional levered lifting;
• and
• c) providing the hand truck with an engageable and disengageable braking structure configured to retard downward movement of the hand truck during upward movement of the hand truck and to control downward movement.