The Wheelift Systems Group of Doerfer Companies manufactures very heavy capacity automatic guided and manually driven, self-propelled, AGVs and in-plant transporters for very large assembly operations. While the Doerfer Companies is an established builder of standard and special wire guided Automatic Guided Vehicles (AGVs). Doerfer is now using Wheelift fluid equalizing suspension technology to dramatically increase their AGV’s practical capacity ranges to carry unlimited weight.   Although wire and laser guidance is still used when interfacing with, or expanding, existing systems, Doerfer now focuses primarily on inertial guidance for many of its larger AGV applications.  Doerfer has adopted the Siemens based Savant AGV guidance technology as being the most practical for the very heavy capacity AGV systems. The manual transporters are controlled by either hand-held pendants or riding operators.  The Wheelift technology based transporters are intended for IN-PLANT heavy assembly operations where loads are normally larger than 50- tons. Due to the cost to manufacture these much more sophisticated transporters, Wheelift based equipment can only be cost-justified in applications where conventional means CANNOT provide the functionality needed --- that is invariably with loads greater than 30-tons in AGV applications, and 80-tons in operator controlled transporter applications. There are three core technologies that must be present to make these heavy capacity transporters and AGVs possible — fluid equalizing suspension, on-center rotation axle assemblies, and computerized steering control.

With Doerfer's extensive custom engineered and integrated systems experience and capabilities, they specialize in turnkey solutions for manufacturing and assembly facilities.  With the Wheelift technology, that would mean assembly of large mining machinery, turbine generators, heat exchangers, furnaces, and the largest of pressure vessels. Other applications include self-loading mold change vehicles for the plastics industries, and shielded containers for radiation waste in ISFSI nuclear processing and storage facilities.  Wheelift™ heavy lifting Self-Propelled In-Plant Modular Transporters (IP-SPMT) offer dramatic new manufacturing and assembly line capabilities to industry for IN-PLANT handling applications.  While the technology is similar to over-the-road-type SPMTs built in Europe by firms like Nicholas, Goldhofer, Scheuerle, Kamag, Cometto, Mafi, and Gussin, Doerfer’s open-center axle Wheelift concept allows designs that are much more compact with much lower deck heights, yet with considerably heavier load carrying capacity per axle.  And, with solid urethane tire assemblies, they are far more suitable for deteriorated floor conditions found in many in-plant assembly and process applications.

Doerfer’s heavy capacity transporters are truly omnidirectional.  Not only do they travel forward and backward, but moving sideways or turning about their own center is standard for all systems.  Straight forward PLC programming code is used for the system's SynchroSteer® package to control vehicle steering and speeds.  Doerfer’s all-directional steer wheel technology is ideally suited for both automatic and manual navigation.  Doerfer also offers Wheelift wheel assemblies to support travel of heavy precision tooling fixtures and scaffolding structures where the Wheelift fluid suspension completely isolates the moving tools from undulations and other irregularities in plant floor surfaces.  Massive structures can move in any direction with no resistance to reversing direction, often emulating precision ground rail movement.  This is functionality that is just not possible with conventional rails, wheels, rollers, or castered systems.

This new heavy lift, equalizing suspension wheel technology is directed exclusively to fully automatic heavy AGV applications and operator driven IN-PLANT transporters. While primarily directed toward ultra-heavy tooling, assembly, and process operations, the usage goes to other heavy applications as well, such as fuselage assembly, injection mold and metal stamping die quick change operations, coil carriers, handling jumbo glass fixtures, parent paper rolls, huge fabrications, and machinery where a manufacturer would like to build larger models and equipment than they now have crane capacity for. A plant can now build massive assemblies in facilities where they literally do not have cranes available at all.

Doerfer's capabilities are applicable to virtually ANY process that requires moving heavy loads in tightly congested areas and spaces that have inadequate headroom for crane coverage.