| 摘要 |
PCT No. PCT/GB94/02251 Sec. 371 Date Apr. 8, 1996 Sec. 102(e) Date Apr. 8, 1996 PCT Filed Oct. 14, 1994 PCT Pub. No. WO95/10728 PCT Pub. Date Apr. 20, 1995The disclosure relates to a viscous damper of the labyrinth ring type for incorporation in a mounting for a TV or video camera for damping pan or tilt movement of the camera. The damper has a stator (10) having a multiplicity of upstanding concentric annular fins (12) and a rotor (17) having a corresponding multiplicity of concentric annular fins (32) projecting downwardly which interleaf with clearance with the upstanding flanges of the stator, the space between the fins being filled with a viscous fluid to provide a resistance to relative movement between the rotor and stator. The rotor is adjusted with respect to the stator by a motor driven lead screw. A speed sensor measures speed of the rotor with respect to the stator and torque applied to the camera by the hand control to pan or tilt the camera is measured by a strain gauge associated with the hand control. A control system is provided for the motor embodying a microprocessor preprogrammed with one or more algorithms coordinating torque and speed. Thus the viscous damper may be controlled to provide a resistance torque to movement which rises generally linearly with speed as detected by the speed sensor to a certain level whereafter the resistance is maintained constant.
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