The invention relates to a self-propelled machine used in the construction and repair of roads, curbs and the like.
The machine receives road-base rock, asphalt, gravel and other road building materials from a dump truck and is capable of transferring the material laterally while moving ahead with the truck for immediate application to the roadbed or for shoulder work, filling trenches, patching or feeding curb machines; or it can be used to store the unloaded material in its own hopper and transport the material to a remote location for application as needed. The machine is self-propelled and supported by three ground engaging wheels. All the wheels are always in engagement with the ground and are suspended so that the frame can be tilted if and as required by the terrain. One of the wheels can also be shifted from a forward, retracted position, for compactness in transporting the machine to another job site, to an after, projected position, providing optimum machine stability in operation.
A customary search turned up the following U.S. Pat. Nos.: t,0030
Although some of the features of the present machine find their counterparts in a piecemeal fashion in the prior art, such as valve-controlled hydraulic pumps and motors for driving the wheels as well as adjustment means providing selective elevation of the wheels, as disclosed in Mauldin, U.S. Pat. No. 4,934,864, the overall construction and operation of applicant's machine is neither anticipated by nor rendered obvious by the six patents, taken either distributively or in combination.
Of especial interest is the unique capability of the left rear wheel of the present machine to perform multiple functions. Among these is the ability to lift or lower the adjacent portion of the frame, plus propelling or retarding the movement of the left side of the frame in advancing or "skid-steering" the machine plus changing the "footprint" of the machine between a larger "footprint" to provide stability in use and a smaller "footprint" for compactness in transporting the machine from place to place. Applicant knows of no such multiple capabilities in any prior art machine.