Download Press Release
Download Hi-res Image


The Matrix Varistop variable torque brake comprehensively addresses the requirements of truck designers, who need trucks to get from point- to- point, fast, and with as small a turning circle as possible. These requirements are often complicated, by the weight of the load carried by the truck, and how high the load is suspended in the air: i.e. the heavier the load, and the higher it is, then the more unstable the truck will be, as its centre of gravity is higher. As a result, truck acceleration and deceleration must be reduced accordingly.

The Matrix Varistop effectively addresses this problem using variable torque braking, where the torque change is stepless. The change in current to produce the torque can be generated from electronics in the truck, and varied dependent on the magnitude of the load and the height at which it is being carried. This allows the truck to be braked from speed to rest as quickly as possible without becoming unstable.

To achieve optimum braking, the Matrix Varistop variable torque brake (the 51PMB range) can be used on the traction motor or the load wheels of fork trucks. With no DC voltage applied, permanent magnets in the Varistop generate a magnetic field, which attracts the brake armature through a multi-disc plate pack and creates 50% of the brake’s rated torque. In this mode the brake is a holding brake.

To disengage the brake, a DC current is applied to the brake coil in the correct polarity, and the current is increased to generate a magnetic field, which opposes the magnetic field from the permanent magnets. This reduces the clamp force at the friction surfaces, and thus the torque generated by the brake. By continuing to increase the current a point is reached when the two magnetic fields balance each other resulting in zero force, thus zero torque. This is the brake state when the truck is in motion.

By continuing to increase the current, the brake again generates an electromagnetic field and a clamp force at the friction surfaces generating a torque and acting now as a service brake. This torque can be increased, steplessly, to the rated torque (twice the holding torque generated by the permanent magnets), by continuing to increase to the full rated voltage and current.

About Matrix: Part Of the Altra Group Of Companies.

In the forklift truck market, Matrix focus on battery powered, electric motor driven trucks for the industrial and warehouse markets. The company supplies to the leading forklift truck manufacturers worldwide, offering very strong design and development support to customers, from engineers with many years of FLT application experience and knowledge. This expertise, combined with ongoing research and the introduction of rare-earth magnets ensures that the overall dimensions of Matrix brakes are kept as compact as possible.

Matrix employs Finite Element Analysis in its designs and also uses sophisticated computer controlled test equipment in its product development, and brake assembly departments. This ensures that well-developed and consistent quality products are supplied.

Matrix quality systems are accredited to ISO 9001 ensuring that product design and development, manufacturing and service are of the highest standard. Matrix is currently in the process of attaining ISO 14001 environmental standards, to minimise its carbon footprint and create a “green” environmentally friendly manufacturer.

About Altra Industrial Motion Inc.
Altra Industrial Motion, Inc, is a leading multinational designer, producer and marketer of a wide range of mechanical power transmission products. The company brings together strong brands covering over 40 product lines with production facilities in nine countries and sales coverage in over 70 countries. Altra’s leading brands include Warner Electric, Matrix International, Wichita Clutch, Stieber Clutch, Twiflex Limited, Bibby Transmissions, Huco Dynatork, TB Wood's, Formsprag Clutch, Ameridrives Couplings, Industrial Clutch, Boston Gear, Marland Clutch, Nuttall Gear, Inertia Dynamics, Warner Linear and Kilian Manufacturing.

Altra Industrial Motion, Inc. (Nasdaq:AIMC), a leading global supplier of clutch brakes, couplings, gearing, belted drives, linear actuators and power transmission components.

                                        ……………..  Ends ………………

For Further information contact: Peter Anderson, Matrix International Ltd, East Mill Road, Brechin, Angus, DD9 7EP. Tel: +44 (0) 1356 602079 Fax: +44 (0) 1356 602060 e-mail:  Web:

For editorial enquiries contact: Brett Davies, DMA Europa Ltd, 2nd Floor, Snuff Mill Warehouse, Park Lane, Bewdley, Worcs. DY12 2EL. Tel: 01299 – 405454 Fax: 01299 403092 E-mail:


[ Return To List]
About the DMA Group Click to Read More