| 摘要 |
A pneumatic actuator includes a cup-shape cylinder body housing a piston and having a generally flat base with a mounting hub projecting outwardly. A piston rod is slidably mounted in the hub and connects to a load such as a damper in an air mixing box. The base is formed with a bearing recess or depression means encircling the hub. The recess defines a spherical sector offset from the center of a complete sphere of the same radius. An annular swivel ring includes an inner diameter adapted to loosely fit over the hub and includes an outer periphery which is generally spherically shaped and defines a central spherical sector having a maximum planar diameter slightly larger than that of the sector defined by recess. The swivel ring is a two-part member having interconnecting slot and projection elements providing a snap joint connection, with the mounting plate firmly clamped therebetween. The swivel ring with the attachment plate fits over the mounting hub. A clamping nut means is secured to the hub with a bearing recess generally corresponding to that formed in the base. An outer head is secured to the cylinder by a suitable snap joint with a peripherial head of a diaphragm rigidly clamped therebetween. A cup-shaped piston is connected to a piston rod by a snap joint which permits free rotation of the rod within the piston. The piston opens into the cylinder and provides a guide for a clamp spring which acts between the piston and the base of the cylinder. The diaphragm ovelies the face of the piston and extends downwardly therebetween to develop a rolling diaphragm construction. |
