The device shown is used for coarse adjustment of the height of an experimental apparatus without a change in its horizontal position. Because of the slip- joint at A, turning the screw does not rotate the cylindrical leg above A. The mean diameter of the thread is 3/8 in. and the coefficient of friction is 0.32. For a conservative design which neglects friction at the slipjoint, what should be the minimum number N of threads per inch to ensure that the single-threaded screw does not turn by itself under the weight of the apparatus?

The device shown is used for coarse adjustment of the height of an experimental apparatus without a change in its horizontal position. Because of the slip- joint at A, turning the screw does not rotate the cylindrical leg above A. The mean diameter of the thread is 3/8 in. and the coefficient of friction is 0.32. For a conservative design which neglects friction at the slipjoint, what should be the minimum number N of threads per inch to ensure that the single-threaded screw does not turn by itself under the weight of the apparatus?

International Edition---engineering Mechanics: Statics, 4th Edition

4th Edition

ISBN:9781305501607

Author:Andrew Pytel And Jaan Kiusalaas

Publisher:Andrew Pytel And Jaan Kiusalaas

Chapter7: Dry Friction

Section: Chapter Questions

Problem 7.57P: The square-threaded screw with a pitch of 10 mm and a mean radius of 18 mm drives a gear that has a...

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