Caliper disc brakes can be used to add holding force in horizontal applications and aid in deceleration at the end of stroke. Caliper disc brakes must be used with an automatic tensioner to function properly.
Determine the load configuration and the holding capacity of the brake.
The following steps will help determine the adequate stopping time and distance for the cable cylinder equipped with a caliper disc brake under various conditions and loads.
HORIZONTAL LOADS
VERTICAL LOADS** and INCLINED LOADS
Figure 1
1.
Select the bore size of the cable cylinder based on load to be moved. Determine load pressure. Set regulator at 25% above load pressure (Pc).
2.
Calculate the unbalanced cylinder force (Fc)only if pressure is applied when braking. If pressure is removed prior to braking, go on to 3.
3.
Calculate the tangential braking force required. This is (Ftr) when pressure is removed prior to braking, or (Fta) when pressure is still applied when braking. Refer to illustrations in Figure 1.
Carefully note conditions:
4.
Calculate the tension required in brake side cable at the time of braking.
In the above expressions (a) can be calculated from:
5.
Calculate the tensioner pressure setting, (Pt) based on the type of load configuration. See Figure 1 and Table 1
6.
Calculate maximum tension in the cable with pressure removed prior to braking. (Ltrm) or with pressure applied when braking (Ltam).
7.
Carefully check that (Ltrm)or Ltam) does not exceed 60% of the cable tensile strength*. If they exceed the 60% figure, either stopping time or stopping distance has to be increased. Repeat steps 1-7.
*Refer to Cable Specifications in the double-acting cable cylinder section for cable tensile strengths.
8.
Calculate the brake operating pressure. See Table 1
9.
If pressure is removed prior to braking, check to see if brake can hold the load if application is either vertical or incline.
Pneumatic Rodless
Band Cylinders™ and Slides
Double Acting
Features
Selection
Cylinder Selection
