Abstract: A surface supported vehicle lift includes at least one independent elevating runway member which accepts loads of varying weights. The runway member accepts uniform or non-uniform loads imposed from a first end to a second end. The runway member includes at least two lift leg assemblies. The lift leg assemblies include hydraulic cylinders and a pump having an electric motor to drive the hydraulic cylinders. Each lift leg assembly also includes pulsed or proportional solenoid valves and position sensors affixed thereto. Synchronizer pumps are provided to equalize flow to and from each lift leg assembly for the runway member, and each lift leg assembly includes pulsed or proportional flow divider bias thereby maintaining lateral and longitudinal synchronization between each lift leg assembly. The surface mounted vehicle lift need not be fixedly attached to a supporting surface, and in addition, may be in moveable contact with the supporting surface.

Abstract: A lift assembly adapted for large vehicles includes first and second lift platforms selectively raised and lowered relative to a base member. Fluid actuated support arms are interposed between the lift platforms and the base member to define a generally trapezoidal arrangement. Segmented bearings are interposed between opposite ends of the support arms and the lift platforms and base member to accommodate tolerance stackup. The lift assembly also includes a sensing assembly that determines if a height differential exists between the lift platforms. If a height differential is sensed, movement of one of the lift platforms is altered to correct the situation. If too great a differential is sensed, further movement of the platforms is terminated. A locking arrangement maintains the lift platforms elevated relative to the base member. A sensing arrangement determines whether the locking arrangement is properly oriented and whether the load is applied from the lift platforms.

Abstract: A lift assembly includes four swing arms interconnecting a base member and lift platform. A hydraulic cylinder selectively elevates the lift platform relative to the base member. A stiff leg also extends between the base member and the lift platform and cooperates with a series of stop blocks for locking the lift platform at predetermined heights above the base member. A link is associated with the stiff leg to selectively support the stiff leg above the stop blocks and permit an operator to move the lift platform between the predetermined heights. The link automatically positions the stiff leg for engagement with the stop blocks if the direction of movement of the platform is altered.

Abstract: A method of measuring a characteristic of a material in a structure is the subject of the present invention. A known stress relationship S=TC/J is utilized in practicing the method of the present invention. In the foregoing formula S=strength in p.s.i.; T=torque force in pounds/inch; C=distance to the point of interest in inches; and J=.pi./2r.sup.4 where J is the polar moment of inertia for a circle of radius r (in inches). A drive head is adhesively secured to a segment of the structure to be tested. A known torque force is then applied to the drive head and this known force is translated into a measurement of the material characteristic utilizing the formula indicated. The method may be utilized to test the ultimate shear strength by failing the material or may be utilized to measure strength up to a design criteria without carrying the material to failure. Other material characteristics may also be measured utilizing the known formula set forth above and other known relationships.