Lock and coupling for securing fire hydrants

Claim 1

A lock and coupling apparatus for use on a fire hydrant, comprising: (a) an inner cylindrical member incorporating a socket cavity extending axially from one end thereof and terminating at a first transverse wall, said socket cavity conforming in shape and size to receive an upstanding post located on the fire hydrant, said post being operatively connected to a valve; (b) cooperative transverse hole and lock pin means extending through said inner cylindrical member at an axial location thereon for fastening said cylindrical member to the post; (c) a first, single, centrally located, nonround recess extending longitudinally from the other end of said inner cylindrical member and terminating at a second transverse wall; said first nonround recess slidably receiving a single conformed lock block of magnetizable material; (d) an outer cylindrical member having an axially extending opening terminating at an end wall forming a shoulder, said opening adapted to receive rotatably said inner cylindrical member and said nonround recess thereof, said outer member further including an upstanding, nonround lug projecting therefrom and being completely closed at an axial location corresponding to the axial location where the lock pin extends through said inner cylindrical member wherein the outer cylindrical member can not be locked with respect to the inner cylindrical member where the axial locations align; (e) a second, centrally located, nonround conformed recess countersunk in said end wall of said outer cylindrical member, said second recess being located opposite said first nonround recess upon positioning of said inner and outer members cooperatively together, wherein said first and second recesses are adapted to receive said magnetizable lock block jointly therein; (f) a ring received in oppositely facing grooves formed in said inner and outer cylindrical members defining a circumferential channel therebetween coupling said inner member to said outer member to prevent relative axial displacement; (g) means for rotating said outer member to open and close the valve of the fire hydrant, said rotating means comprising a wrench having a handle including an end located socket adapted to receive said nonround lug projecting from said outer cylindrical member, said wrench further including conforming nonround lug engaging means within said socket for engaging said nonround lug projecting from said outer member; magnetizing means completely enclosed within said socket for magnetically attracting said magnetizable lock block; wherein said magnetizable lock block joins said inner member and outer member for joint rotation upon engaging the lug engaging means with the lug.