Abstract: A ring-type meter lock including a resilient ring, first and second ends on the ring, a lock housing on the first end, a first slot in the lock housing, a latch unit in a threaded bore in the lock housing, the latch unit consisting of a threaded plug and a stem slidably mounting a latch with a spring between the plug and the latch which biases the latch into the first slot, an apertured tongue on the second end of the ring enterable into the first slot, at least one second slot in the tongue for receiving the spring-biased latch, and a key-receiving configuration on the threaded plug.

Abstract: A noncircular-based undulating key-receiving configuration, opposed undulating side walls in said configuration, a centerline within said side walls, with the centerline of the configuration lying within inner and outer noncircular perimeters. A key-receiving configuration containing a first undulating configuration within a second undulating configuration. A key having a first body insertable within a second body with both bodies having undulating key configurations thereon. A key-receiving groove having chamfered edges.

Abstract: A tamper resistant construction for preventing unauthorized actuation of the hydrant nut of a fire hydrant by causing any lateral pounding or upward forces applied to the tamper resistant construction to be transmitted directly to the hydrant body cover of the fire hydrant including a packing nut threaded into the hydrant body cover proximate the hydrant nut, a hydrant nut actuating body located within the packing nut and mounted on the hydrant nut in turning relationship therewith, a shroud permanently or removably rotatably mounted on the packing nut in closely spaced relationship to a cap rotatably mounted on the hydrant nut actuating body, and a configuration on the hydrant nut actuating body between the cap and the shroud for receiving a special wrench.

Abstract: A tamper resistant construction for a fire hydrant including a hydrant nut actuating body for mounting on a hydrant nut, a shroud rotatably mounted on a first end portion of the hydrant nut actuating body, a cap rotatably mounted on a second end portion of the hydrant nut actuating body, a wrench-receiving portion on the hydrant nut actuating body, a spring mounted within the hydrant nut actuating body and secured to the cap for biasing the cap over the wrench-receiving portion, and a specialized wrench for retracting the cap and engaging the wrench-receiving portion on the hydrant nut actuating body to thereby turn the hydrant nut actuating body and a hydrant nut coupled thereto. The shroud may be removably mounted on the hydrant nut actuating body to permit access to set screws which secure the hydrant nut actuating body to the hydrant nut.

Abstract: A tamper resistant construction for a fire hydrant including a hydrant nut actuating body for mounting on a hydrant nut, a shroud rotatably mounted on a first end portion of the hydrant nut actuating body, a cap rotatably mounted on a second end portion of the hydrant nut actuating body, a wrench-receiving portion on the hydrant nut actuating body, a spring mounted within the hydrant nut actuating body and secured to the cap for biasing the cap over the wrench-receiving portion, and a specialized wrench for retracting the cap and engaging the wrench-receiving portion on the hydrant nut actuating body to thereby turn the hydrant nut actuating body and a hydrant nut coupled thereto.

Abstract: A tamper resistant construction for preventing unauthorized actuation of the hydrant nut of a fire hydrant by causing any lateral pounding or upward forces applied to the tamper resistant construction to be transmitted directly to the hydrant body cover of the fire hydrant including a packing nut threaded into the hydrant body cover proximate the hydrant nut, a hydrant nut actuating body located within the packing nut and mounted on the hydrant nut in turning relationship therewith, a groove in the packing nut, a plurality of studs extending between the hydrant nut actuating body and the groove in the packing nut, a shroud rotatably mounted on the hydrant nut actuating body in closely spaced relationship to a cap rotatably mounted on the hydrant nut actuating body, and a limited space between the cap and the shroud for receiving a special wrench.