Abstract This lock consists of only a stepped cylindrical body the reduced lower shank portion of which fits snugly in the upper end of the stand-pipe with the shouldered upper end resting on the stand-pipe so as to locate the radially movable bolt at the exact level of a keeper hole drilled radially in the upper end portion of the stand-pipe. A press fit ring applied to the outside of the pipe closes the outer end of the hole to protect the lock against dirt and moisture from outside the pipe. A key in possession of an authorized employee of the city water department serves to unlock the lock so it can be removed when a T-wrench of suitable length to reach down below the frost line is to be applied to the stem of the shut-off valve through the stand-pipe to open or close the valve. The usual screw-on cover cap at ground level threads onto the upper end of the stand-pipe and serves to conceal and protect the lock against being tampered with. Usually the aforesaid T-wrench serves also to unscrew this cap and replace it.
In a service cut-off box comprising a pipe through the open end of which a long handled wrench for manually opening or closing a cut-off service valve is operable when a cover plate is unthreaded from the upper end of said pipe to expose the open end, means for preventing unauthorized access to the open end of said pipe comprising a cylindrical lock body having a smaller diameter lower portion fitting close inside and effectively plugging the open upper end of said pipe and an upper enlarged diameter portion resting on the open upper end of said pipe normally concealed and shielded by said cover plate, the latter portion of said lock body projecting upwardly from the open upper end of said pipe, key operable locking means in said body operable by entry of a key in a keyhole accessible at the outer end of said lock body, a flanged protective cover plate for said lock smaller in diameter than said cover plate and having a telescoping sealing fit downwardly on the cylindrical lock body to prohibit entry of dirt and moisture downwardly into the lock body through the keyhole, said lock means upon rotation of the key extending or retracting a bolt movable substantially radially relative to the inner end portion of said lock body into a radial keeper hole drilled into the pipe in register with the bolt.
Claim 2
Dependent Claim
230 words
In a service cut-off box comprising a pipe through the open end of which a long handled wrench for manually opening or closing a cut-off service valve is operable when a cover plate is unthreaded from the upper end of said pipe to expose the open end, means for preventing unauthorized access to the open end of said pipe comprising a cylindrical lock body having a smaller diameter lower portion fitting close inside and effectively plugging the open upper end of said pipe and an upper enlarged diameter portion resting on the open upper end of said pipe normally concealed and shielded by said cover plate, the latter portion of said lock body projecting upwardly from the open upper end of said pipe, key operable locking means in said body operable by entry of a key in a keyhole accessible at the outer end of said lock body, a flanged protective cover plate for said lock smaller in diameter than said cover plate and having a telescoping sealing fit downwardly on the cylindrical lock body to prohibit entry of dirt and moisture downwardly into the lock body through the keyhole, said lock means upon rotation of the key extending or retracting a bolt movable substantially radially relative to the inner end portion of said lock body into a radial keeper hole drilled into the pipe in register with the bolt.
Claim 3
Dependent Claim
47 words
The structure as set forth in claim 1 including a ring encircling the pipe and covering the outer end of the keeper hole to exclude dirt and moisture without interfering with the freedom of operation of the bolt in entering or being retracted from the keeper hole.