Features, Safety systems and solutions, Work health and safety

What’s stopping your conveyor?

johnson industries

Innovative design and high-quality standards set Johnson Industries’ industrial brake systems apart.

Essential to many mining operations, conveyor systems allow the transport of thousands of tonnes of ore across vast distances, or up and out of underground mines, every hour. But because these machines rarely stop, maintenance of their brakes can be unintentionally overlooked. 

“Ideally, a conveyor braking system is limited to use during maintenance operations. Only when overspeed conditions, overload conditions or mechanical failures occur do brakes come into play,” Johnson Industries chief executive officer Lawrence Johnson told Safe to Work.

When the need arises to halt a conveyor, mine sites want to know that their brake systems will be up to the task.

Johnson Industries’ brake systems can be found at mine sites across Australia in conveyor systems, ball mills, and semi-autogenous grinding (SAG) mills. They can also be found in rail-based ore transport systems in the form of wheel grippers, and in many general crane applications. The company has grown its expertise for over a century in the US, and is now expanding into the Australian market. 

Johnson Industries offers multiple types of brake products. Most are spring-applied (fail safe), but some are available with hydraulic and spring actuation for use as service brakes. 

Multiple actuating technologies are available: hydraulic, pneumatic, electrohydraulic, magnetic, and of course, hand operated. These brakes are largely designed for use with discs; however, drum brakes are available for smaller applications. 

Hydraulic brakes can be ordered with power units, electrohydraulic brakes with proportional control units, and magnetic brakes with power management units for minimum power consumption and maximum surge protection at run time.

A limited number of hydraulically and/or electrically actuated service brakes are available with self-adjusting mechanisms to maintain the correct air gap between pads and disc. With a properly fitted self adjuster, machines can run for longer without requiring maintenance owing to reduced brake torque as pads wear.

Designing to maximise the time between maintenance operations is a critical part of quality. Direct-acting (DS) brakes have removable actuators, permitting shoe and/or actuator replacement without the removal of the entire brake movement. Lever brakes offer the same feature and benefit.

A distinction can also be drawn between service and parking or emergency brakes. 

Generally, self-adjusting mechanisms are not included on parking or emergency brakes, as braking surfaces do not wear very quickly. This does not excuse the requirement for periodic inspections and maintenance. 

“An automobile parked for year or more will likely have difficulty starting and running, but if driven daily it will probably function with little or no service required. It’s the same with industrial brakes,” Johnson said. 

“Accidents occur if equipment is not maintained, even if not in regular use.”

Johnson Industries offers support in the form of recurring check-ups and training to ensure proper brake function. Written manuals with detailed maintenance procedures are included with all brakes.

On request, the company will provide maintenance seminars, on-site installation supervision, and start-up support. Inspections, adjustments, and maintenance services are also available. 

This feature also appears in the May-June issue of Safe to Work.

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