| 摘要 |
A linear actuator for providing a thrust force for actuating various movable members, such as, for example lever arms, cranks, slides and valve flaps. The thrust force is applied by an extension rod that is arranged within a housing so as to extend in an axial direction along the housing and out from the housing. The extension rod has a load connector mounted on the end outside of the housing for connection to the movable member to which the thrust force is to be applied. A drive screw is attached to the extension rod so that rotation of the drive screw is translated into an axial displacement of the extension rod. A drive motor serves to rotate the drive screw. Either when a blockage of the movable member occurs or when the extension rod has reached the end of its path of travel, any attempt for continued movement of the extension rod significantly increases the thrust force applied to the rod. In order to prevent the continued application of such force and resulting damage to the system, a thrust control mechanism is provided for terminating operation of the drive motor when the thrust force exceeds selected thrust force limits. The thrust control mechanism includes an adjustable device for enabling the thrust force limits to be selectively adjusted. Such adjustments for selecting the limits of the thrust force can be made without requiring disassembly or any adjustment to the major working mechanism of the linear actuator.
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