| 摘要 |
1,157,966. Frictional dampers. SOC. FRANCAISE D'EQUIPEMENTS POUR LA NAVIGATION AERIENNE. 28 March, 1967 [29 March, 1966], No. 14180/67. Heading F2S. [Also in Division G1] An indicating instrument 1 having a rotatable shaft 10 incorporates a device for damping and for improving its sensitivity comprising a disc 2 carried by the shaft 10 and having a rim 2A which is engageable by the end 12 of an arm 5, 7 of a striker 3, the end 12 being reciprocated into and out of contact with the rim 2A to impart repeated blows thereon and thereby cause transitory frictional forces to damp the rotation of the shaft 10, the mechanical shocks caused by these blows also assisting the shaft to overcome frictional forces in its mounting to improve the sensitivity of the instrument 1. The arm 5, 7 is in the form of a pivoted bell-crank lever and the end 12 of arm, which is of plastics or rubber, is biased away from the rim 2A by a spring 6. An electromagnetic coil 8 is fed with alternating current so as to reciprocate the arm 5, 7 about its pivot. As an alternative an electric bell type of actuator fed with direct current may be employed or a flexible blade on which is disposed piezo-electric material fed with alternating current to cause vibration of the blade. The device is described as being applicable to the indicator of a gyroscopic artificial horizon, or to the linear movement of a spring mounted weight in an accelerometer.
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