SYM-METRIC ACTUATOR MODELS Sym-metric Actuator . Sym-metric Actuators with Anti-Backlash Feature Shell Cap Sym-metric actuators are available with anti-backlash nuts for applications where a reversal of loading from tension to compression is encountered. Anti-Backlash Features:• Reduction in the vertical backlash between the screw and the worm gear nut to a practical minimum for smoother, more precise operation and minimum wear. • Acts as a safety device, providing a dual nut load carrying unit, when the worm gear becomes worn. • Wear indicator for critical applications. The anti-backlash feature can be maintained by adjusting the shell cap until the desired amount of backlash is. | B a . SYM-METRIC ACTUATOR MODELS . Sym-metric Actuators with Anti-Backlash Feature Sym-metric actuators are available with anti-backlash nuts for applications where a reversal of loading from tension to compression is encountered. Anti-Backlash Features - Reduction in the vertical backlash between the screw and the worm gear nut to a practical minimum for smoother more precise operation and minimum wear. Acts as a safety device providing a dual nut load carrying unit when the worm gear becomes worn. Wear indicator for critical applications. The anti-backlash feature can be maintained by adjusting the shell cap until the desired amount of backlash is achieved. To avoid binding and excessive wear do not adjust lifting screw backlash to less than mm refer . Optional Anti-Backlash actuators are available with inverted screws to increase mounting flexibility as access is required to the shell cap to allow backlash adjustment. The bottom pipe for these actuators screw into the shell cap. For keyed actuators the position of the keyed hub remains as shown. Standard Dimensions mm Model Standard R Keyed Y A B C D E F G ST025-R Y 76 15 172 60 50 Raise 35 ST050-R Y 100 25 217 75 60 Raise 42 ST100-R Y 127 28 252 90 76 Raise 52 ST200-R Y 145 34 299 102 95 Raise 63 Torques and Efficiences for Standard Anti-Backlash Actuators Model ST025-R ST050-R ST100-R ST200-R Capacity kN 25 50 100 200 Lifting Screw No of Starts Single Double Single Double Single Double Single Double Torque at Full Load Nm Standard 21 28 60 82 124 168 279 367 Option 1 17 23 48 66 155 211 352 461 Option 2 9 12 26 36 63 86 142 187 Static Actuator Efficiency Rating Standard Option 1 Option 2 Weight with base raise of 150 mm Kg 74 Note - 1. Refer . for Sym-metric product code structure. 2. For loads from 25 to 100 of actuator .