Belt Maintenance

Belt Clamps

Belt clamping devices are used to firmly secure a conveyors' belt to a fixed point to prevent it moving during maintenance.

Belt clamps are 'temporary' items which can be fitted at almost any location along the carrying- or return-side of the conveyor. The tools are mobile, meaning that they are usually kept in the maintenance workshop and are carried to the relevant conveyor by the maintenance team i.e. the clamping tools are not a permanent fixture on a conveyor, unlike a belt arrestor for example.

i. Anatomy of a belt clamp set

A typical belt clamp comprises the following components (courtesy of MATO) :-

A pair or aluminium or steel beams which are longer than the belt is wide and a pair of shackles which are profiled to slide along the beam to suit the belt width.

The shackles comprise lugs onto which a steel rope or hoist can be attached in order to pull the clamped belt if necessary, or to fix the clamp in the required position.

As the pulling force is applied to the shackles, the shackles impart a clamping force to the belt via the beams by virtue of the design of the shackles. It therefore follows that the greater the pulling force applied, the greater is the clamping force.

Belt clamps should be selected on the basis of the width and thickness of the belt as well as on the tension to which the clamp unit is to be subjected.

Clamps should therefore be purchased from reputable suppliers to ensure that the clamps are suitable for the application and are able to withstand the tensile load. Factory tests can be called for to confirm the capability or rating of clamp sets.

ii. Selection / rating of clamp sets

As has been indicated above, clamp sets should be selected on the basis of the belt(s) to be clamped as well as the tension which the clamp set is expected to withstand.

Some guidelines for MATO-type clamp sets are outlined below :-

Clamp Set Type / Model
The MA 1.0 belt clamp set has a safe working load 1.0 ton; consists of aluminium beams and steel shackles. The clamps can be pulled either centrally with a 1 ton pulling device or from the sides with two 0.5 ton pulling devices. The MATO belt clamps for belts used in industry are proof tested to 1.5 times the sake working load to ensure that no damage or permanent deformation occurs.
The MS 2.0 belt clamp set operates at safe working load of 2.0 ton. The clamping beams and shackles are produced from steel. The clamps can be pulled with a single 2 ton pulling device using a central connection or alternatively, with two 0.5 ton pulling devices using side connections. The MST 2.0 belt clamp set is designed for use on troughed flat belts. The clamp set is the same as the MS 2.0 with the exception of the side shackles. The shackles open to allow clamping of the beams on troughed belts and are closed using a bar to lever them together, a pin is inserted to lock the shackles.
The MATO belt clamps are designed for safe clamping of conveyor belts. The belt clamps are manufactured and tested to quality assurance procedures. Specially designed to hold the belt at 3 times the safe belt working load. After final assembly each belt clamp is proof tested on a special test rig to twice the safe working load to ensure that no damage or permanent deformation occurs.These heavier duty belt clamps are available in 3 rated working loads :-  Safe working load 15kN 30kN 60kN No. of pulling devices 2 x 0.75 t 2 x 1.5 t 2 x 3 t Weight of belt clamp set 32 kg* 68 kg* 128 kg* * This example is set for 1200mm belt clamp set. Standard widths are 1000mm and 1200mm, other sizes are available to order. Please note for safety reasons the clamps should only be used with the correct width of belt, i.e. a 1200mm belt clamp must only be used on a 1200mm belt.