By Lynn Bostrom | Feb 01, 2011
Auto Crane Company, located in Tulsa, OK, developed the very first auto crane in 1958 by placing a crane in the trunk of a car. This work-truck industry pioneer has since produced some of the most reliable cranes and crane-service bodies on the market. Continually striving to provide new and innovative products to the market, Auto Crane has introduced a number of new cranes over the years. Providing both electric and hydraulic cranes, Auto Crane now offers models with the capability of lifting up to 14,000 pounds. The company’s products are known for their innovation and versatility, maintaining its number-one position in the industry today. Auto Crane, a subsidiary of Ramsey Industries, introduced its newest innovation to the market: a totally proportional crane control system in partnership with Magnetek, Inc.
The challenge for Magnetek was to replace Auto Crane’s existing pistol-grip wireless hydraulic control and outdated hydraulic system. The old control system required an operator to use two hands to depress a proportional trigger and an on/off thumb trigger control that offered primarily single function control. The truck-mounted cranes handle a variety of lifting requirements for service technicians and this configuration was cumbersome and inefficient. In its original configuration, the trucks utilized basic hydraulic controls with limited proportional functions, which caused undue boom stress loads and the inability to perform multiple proportional functions at the same time. The radio remote control did not provide any crane status information, and was not scalable to meet unique user demands.
The Old System
The old mobile hydraulic control system employed on the crane trucks was similar to that in use by the majority of the industry, and includes a pistol grip transmitter, series hydraulic system, single pressure switch and series circuits.
The system utilized a pistol grip transmitter with thumb actuated toggle switches that activated only when the proportional trigger was pressed. In the event that the toggle was accidently released, the hydraulic system could slam shut without ramping down resulting in an instant stop on the crane and load. The severe shock to the boom and truck often damaged the boom.
The old hydraulic system was in series causing flow degradation when two or more functions were engaged at the same time. The system’s poor metering of the hydraulic oil caused the flow rate to drop in half to the original function when an additional function was put into operation. Series configuration is considered an outdated technique for hydraulic control and is a common problem with many of the systems currently in the field.
All of these issues were rectified by the new system designed and manufactured by GSNA and Magnetek for Auto Crane’s numerous mobile hydraulic truck sizes, configurations and applications.
The New System
Magnetek provided the state-of-the-art crane control and operating systems that offer fully proportional hydraulic valve control, with multiple speed scaling and the ability to operate multiple functions of the crane at one time. The team moved technologies once only found in expensive high-end trucks to economical mid- to lower-end models. The new system is comprised of three major components: the hydraulic system, the hand-held transmitter, and the receiver. The three major components work together to produce a crane load management system that is extremely user friendly to the operator and provides for the efficient and safe operation of the crane.
The new hydraulic system is scalable from 5,000 pound cranes to 14,000 pound cranes. The new design allows for a change in speed and performance parameters through the entire load range. One valve bank is used through Auto Crane’s entire product range with the only change being the electric current parameters set through the control. A crane’s profile is pre-loaded into the controller and every crane has its own profile. So, the controller reads and matches the correct control profile for each crane – this is where the marriage of the hydraulics and electronics really excelled.
The system significantly improves the truck’s stability and safety by implementing a total machine control system that monitors and coordinates all machine movements. Level, pressure and proximity sensors measure positions, determine loading and monitor speeds of critical machine functions. I/O modules provide electro-hydraulic proportional control of the crane functions. Wireless technology is a proven solution for flexible remote machine control. Integrating the wireless controller with the CAN network, including operator control, provides a cost effective, efficient and safe control network for a machine operator.
Tiffin Loader Cranes primary focus is providing innovative lifting, loading, and handling solutions for customers unique material handling problems. Magnetek and S. G. Morris created a system solution that offers an integrated package of wireless control and hydraulics, allowing for smoother and easier operations. Enhancing equipment performance and simplifying adjustment capabilities were the goals of the new system install on the industrial scale certifying equipment.
The Vacall division of Gradall Industries, Inc. provides superior jetting and vacuum solutions for various applications including small, local maintenance such as street sweeping, and large-scale cleanup efforts like the ones in progress along the New Jersey shoreline in response to Hurricane Sandy. Seeking to transfer the majority of their products to CAN-bus based controls, Vacall used Magnetek's radio remote controls and receivers to implement a product-wide replacement of wireless transmitters and receivers.