| 摘要 |
In a door operator, an arm linked to a swing door is connected to shaft 43 which is rotated by an electric, e.g. DC, motor via worm gear transmission 32, adjustable belt 36 and spur gears 40, 42 to open the door. Shaft pinion 44 slides rack shaft 52 to compress an adjustable door - closing spring. The door arm may be mounted on either end of shaft 43. Motor voltage control is described. The position of the motor alongside belt 36 and above the spring gives a compact operator. |
