Valve lock

Abstract

Disclosed is a lock for a valve having a stem which by rotation controls the opening and closing of the valve. The lock essentially comprises a housing having a first opening therein to receive the stem and a second opening; a locking member is disposed in the second opening and comprises a terminal portion which in its closed position contacts the stem and prevents the stem from rotating, a middle portion connected to the terminal portion and having a periphery substantially equal to the greatest periphery of the second opening, and an end portion connected to the middle portion and having a periphery less than the greatest periphery of the second opening. A spring is disposed within the second opening about the end portion and tends to force the terminal portion into its locking position in contact with the stem to prevent rotation of the stem whereby a force must be exerted axially along the locking member against the pressure exerted by the spring in order to move the terminal portion out of contact with the stem in order to permit rotation of the stem to open the valve.

Dependencies are inferred from the claim text.