Sum of the parts

“Each machine has its own personality”, says Wayne McDonald, JLG's senior vice president - engineering, when describing not only access equipment behaviour in general, but also the important 'feel' of an access platform. Where in the past “...these machines were controlled by hydraulics, now primarily electronic systems control access equipment”, Mr MacDonald says, describing a major, continuing design evolution.

Hydraulic component suppliers have been integral to that transition. Consider HydraForce Hydraulics, the Chicago, Illinois-based company that has supplied valves - notably the cartridge type - for over 25 years. It first moved into electronics six years ago in cooperation with Axiomatic, of Finland, to provide controllers for sets of stack valves, and last year started working with another partner, unnamed, to offer electronic control systems for aerial platform manufacturers.

“We can achieve a great deal economically using electronics; particularly when we combine our offerings with customers' elements”, says Martin Birchon, application engineer with HydraForce.

Poclain Hydraulics, the French supplier of hydrostatic drive components, is also firmly entrenched in electronics. For example, it has expanded its SmartDrive range of controllers to allow manufacturers, distributors, and possibly even rental companies, to modify the transmission performance built in during production. The system requires no programming skill and creates, using a PC, the machine code that determines a wide range of operating parameters, including speed, acceleration, and braking and steering rates.

Smooth movements, especially starts and stops, are much-desired characteristics of access equipment ‘personality'. Aimed at delivering that is TTControl's new TTC 200 input/output (I/O) controller, which platform manufacturers can programme to match their selected devices. The model is attractive to OEMs, says the Italian company, because it complies with safety standards IEC 61508 SIL (Safety Integral Level) 2 and 3.

I/O controller

Axiomatic also has a new I/O controller, the AX021100 valve controller. It accepts control signals through two CAN and two RS-232 ports and inputs from eight analogue and eight digital channels. The device generates 12 proportional outputs and four more on/off ones, and OEMs can determine the control logic for its integral processor, too.

Mechanisms to slew MEWP turrets in response to signals from controllers also determine machine behaviour. Bonfiglioli Trasmital's new offering meets a common need of OEMs, described by Jean-Paul Zanussi, director of its transmissions division: “[They] all want the same thing, increased capability in a smaller envelope.” Trasmital has combined its MG series of hydraulic orbital motors and its 700 T series reduction units to integrate rotation and control in a smaller, more precisely controlled, hydraulic gear motor unit. It includes a control valve chosen to maximise precision of position control, important for booms with large outreach, or to reduce transient loads in the system, particularly important when moving payloads at the end of long-reach booms.

It is not just control systems that contribute to personality, at least in the view of Italian engine manufacturer Lombardini. It describes the first in a series of diesel versions of its 15LD single-cylinder range as “silenced”. Although the 349 cc displacement 350S engine outputs 4.4 kW, the company touts its reduced emissions and low noise, achieved by unidirectional flow of the injection pump and multi-bore injector to optimise combustion. Engine start-up is easy, says the company, even at temperatures down to -10°. Options to allow OEMs to extend the ‘personality' of this engine include: electric starting, remote accelerator and stop control, an hour meter, and a sensor that detects air filter blockage.

Giving lift mechanisms smooth movement and preventing the ‘shakes' during initial motion are (engineering) plastic components, often filled with speciality lubricants, from Quadrant Engineering Plastic Products of The Netherlands. These sliding blocks, which bear the high loads of high-capacity, high-lift scissor platforms, “...are a cheaper and more effective alternative to rollers”, says Michiel de Schipper, sales manager for Quadrant. Impregnated lubricants release as the contact surfaces of the blocks wear to continuously lubricate the mechanisms and also reduce ‘chatter'.

On-board chargers for electric-driven platforms have become essential for convenience, and Belgian company Dyno Europe has introduced a range of waterproofed chargers, the AQ-tron high frequency series. Charging capability spans 9 A at 12 V to 48 A at 17 V and includes batteries deeply discharged to 1 or 2 V levels. The units cost from €100 to €240.

Axiomatic's new on-board charger, the AX090000, is also is waterproof, and it charges up to 10 A at 30 V. It is microprocessor-controlled and monitors battery temperature to prevent overheating, as well as reporting voltage and charge current data over CAN bus to the vehicle's control system.

All in all, new components span a broad range of the pieces and systems that comprise access equipment. Each contributes, perhaps unseen but importantly, to the performance, the ‘personality', that differentiates models in fleets around the world.