Curtiss-Wright’s Industrial division – including its legacy brands of Arens Controls, Penny & Giles, PG Drives Technology and Williams Controls – is a recognized leader in providing components and sub-systems that enable customer specific solutions for a wide range of material handling equipment, including pallet/stacker trucks, reach trucks and counterbalance trucks.
For new lift truck designs, the industry has moved away from discrete hydraulic controls to fully electronic operator controls, such as those offered by Curtiss-Wright’s Penny & Giles and Williams Controls brands. These electronic controls offer huge improvements in vehicle reliability and maximum operational comfort for the operator. As a result, the use of electronic control can help to improve the productivity of lift trucks and reduce operator fatigue.
Many vehicle controls are now designed to incorporate multiple functions with the use of just one hand. These controls often incorporate push-button switches, rotary thumbwheels and joystick paddles and levers, which variously offer switched and proportional control of the vehicle’s lifting features.
Penny & Giles branded joystick controllers – such as the JC2000 and JC6000 – are available in single- and multi-axis configurations and can be specified with multiple handle options to provide proportional control within the human-machine interface (HMI) for numerous material handling applications. Linear, rotary and tilt sensors are also suitable for numerous industrial vehicle applications. Complementary systems from the Williams Controls brand also include lever-operated and rotary electronic hand controls, standard and customizable heavy-duty industrial joysticks and contact and non-contact rotary position sensors.
While a lift truck’s attachments can be controlled by lever-, finger- or hand-operated joystick controllers, the traction and motion of the vehicle itself requires a different type of control and products and systems from Curtiss-Wright’s PG Drives Technology and Williams Controls legacy brands are ideal for these applications.
For battery-operated lift truck applications, the PG Drives Technology C3 and C3pump motor controller range is ideal for small industrial vehicle applications including Class 3 pallet trucks and stackers.
The C3 is a compact and cost-effective AC motor controller available in two power options (200Arms and 250Arms at 24Vdc) and primarily intended for Class 3 pallet trucks and stackers, but equally suitable for small ride-on machines. It can be quickly matched to any AC induction motor via a simple, three step auto-commissioning sequence; and can accept multiple types of throttle connections, including 2- or 3-wire resistive and voltage. Integrated software controls all hydraulic functions and can easily cater for interlocking of drive with lift/lower. Hydraulic functions can also be disabled in response to certain conditions such as a low battery voltage. This capability reduces the possibility of battery damage as a result of deep-discharge. To ensure maximum efficiency, an intelligent Hill-Hold algorithm only draws power from the battery if the vehicle starts to roll, removing the traditional requirement for a brake switch.
The C3pump combines the 200/250Arms AC traction drive of the C3 with a 330A DC pump drive for controlling the lifting hydraulics. Designed with all the specialist features required for efficient and precise control of modern day stackers, C3pump features include multiple 2A outputs (for proportional valve, solenoid valves, electro-magnetic brake, line contactor and horn), 2 analogue inputs and 8 switch inputs. The C3pump is also CAN tiller compatible as standard.
Other recent innovations in the C3 motor controller range include 36V and CE-marked versions.
Operating from a 36V battery supply, the C3-36V is an advanced, compact, AC traction controller. Constructed using UL approved materials throughout and designed to comply with UL 583, the controller is equally suitable for other small, ride-on vehicles operating from 36V batteries.
The C3-CE retains all the features and benefits of the original C3, but has been CE marked as a safety component and designed with EN ISO 13849 Category 3 hardware architecture – including dual microprocessors, dual inputs and a dedicated B+Safe output. This provides a safer and more convenient approach that, unlike the conventional and widely-used Category 2 architecture, doesn’t require the safety function to be checked at ‘machine start-up’ and ‘prior to the initiation of any hazardous situation’, which can be inconvenient and potentially dangerous.
Additionally for battery-operated applications, the Sigmadrive range of advanced, high-efficiency controllers for AC induction and DC motors provides smooth and predictable speed control of permanent magnet traction motors across a wide range of system voltages and power ratings. Their advanced design includes features such as IMS technology, high-resolution current measurement, CANbus communications and extremely low heat dissipation. The Sigmadrive has been developed for use in a wide range of electric vehicle applications including lift trucks and industrial, utility and mobile elevating work platforms.
For throttle inputs to drive the ride-on lift trucks, the Williams Controls WM-528 electronic floor pedal mounts flush with the floor and is designed specifically for applications that require a very low profile while maintaining quality and performance standards. Structural components are manufactured from glass reinforced nylon and corrosion resistant steel, making them ideal for more rugged material handling applications where severe conditions exist and drive-by-wire pedal control is desirable.
For open cab applications, the robust design of the floor-mounted Williams Controls WM-575 Hall-Effect rocker pedal makes it extremely durable and provides outstanding performance. Programming of the pedal’s sensor can achieve a highly-accurate output and provides a ratiometric signal that is interpreted by the vehicle controller. It is designed for fore and aft drive and can be customized for side-to-side movement.
Finally, a typical application for discrete no-contact rotary position sensors is on the new generation of articulated forklift trucks used in narrow aisle warehouses. These warehouses have a reduced aisle width, allowing increased storage space within the same building footprint. The Penny & Giles NRH275DR is a typical two-part rotary sensor that is fitted within the articulating mechanism to provide angular position feedback to the vehicle’s control system. The NRH275DR is a low profile sensor housing that is activated by a separate magnet assembly, providing wear-free operation in angles from 20° to 360° and dual electrical signals for improved reliability.
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For more information on Curtiss-Wright Industrial products, visit www.cw-industrialgroup.com or call +44.1425.271444.
About Curtiss-Wright Corporation
Curtiss-Wright Corporation (NYSE:CW) is a global innovative company that delivers highly engineered, critical function products and services to the commercial, industrial, defense and energy markets. Building on the heritage of Glenn Curtiss and the Wright brothers, Curtiss-Wright has a long tradition of providing reliable solutions through trusted customer relationships. The company employs approximately 8,400 people worldwide. For more information, visit www.curtisswright.com.