| 摘要 |
Apparatus and method for jacking and dollying a vehicle wheel assembly, while the assembly remains affixed to the vehicle, the wheel assembly including a pneumatic tire, a wheel and an axle. The apparatus features a "U" shaped framework having telescoping body section members to which orthogonally extending arms are attached. Wheel assembly engaging elements in the form of roller assemblies are mounted on the framework arms for engaging the tire of a wheel assembly located therebetween for lifting. The apparatus also includes an actuator mounted on the framework body section members for driving the roller assemblies against the wheel assembly tire to cause left, and form the framework and roller assemblies into a carriage for retaining the wheel assembly. Still further, the framework is mounted on casters to enable transport of the supported wheel assembly and framework. The actuator is preferably foot operated and includes a bi-directional, double pawl, lever ratchet mechanism having a lever means pivotally mounted to one body section member together with a first and a second pawl, and a rack provided at the other body section member. The actuator also includes direction control elements having a first setting to enable the apparatus to lift the wheel assembly, and a second setting to enable the apparatus to lower the wheel assembly. The method features steps for driving a plurality of wheel engaging elements, at least one of which includeds a roller assembly, against the tread face of the tire of the wheel assembly to be lifted by leveraging for a predetermine distance the coupling member of one wheel engaging element from a fulcrum located on the coupling member of another wheel engaging element, then bracing the coupling members against separation, and thereafter, resetting and re-leveraging to successively drive the wheel engaging elements against the wheel assembly to produce lift. |
