| 主权项 |
1. A door operator comprising:
an installation box having:
a housing having a top, a bottom, an assembling space and an opening communicating with the assembling space; anda lid mounted in the opening and covering the assembling space; an operating mechanism rotatably connected with the installation box and having
a shaft rotatably mounted on the top of the housing through the bottom of the housing;a gear mounted on the shaft, driven by the shaft and having a rotation axis;a swing arm having two ends, one of the two ends of the swing arm pivotally mounted on a top end of the shaft and outside the housing;a rack connected to the other end of the swing arm; a pneumatic apparatus installed in the assembling space and having
a cylinder having an inner space and an insertion hole communicating with the inner space;a piston rod being moveable and mounted in the insertion hole of the cylinder;an adjusting rod connected with the piston rod and having an air-in slit longitudinally formed in a periphery of the adjusting rod;a piston block mounted around the adjusting rod and having a first face, a fitting hole, an abutment recess, multiple air outlets and an air inlet; the first face defined at one side of the piston block, the fitting hole formed in a center of the first face and the adjusting rod fitted into the fitting hole, the abutment recess formed in the first face of the piston block and has a bottom, the air outlets formed through the bottom of the abutment recess and arranged circularly, the air inlet mounted through a periphery of the piston block and corresponding in position to and communicating with the air-in slit;a sealing ring mounted in the abutment recess and covering the air outlets;a clutch ring mounted around the adjusting rod and engaged with the piston block;a first spring abutting between the clutch ring and the piston rod;a second spring mounted in the abutment recess and abutting between the sealing ring and the clutch ring; and a moveable sleeve movably mounted around the cylinder and connected with the piston rod, the moveable sleeve having a gear face and a central axis, the central axis of the moveable sleeve being perpendicular to the rotation axis of the gear, and the gear face correspondingly engaged with the gear. |
