Floating alarm unit for pool or spa

Claim 1

In a pool or spa alarm unit, the combination comprising: (a) a float body adapted to float on a pool of water, said body being annular and forming a central vertical through opening, the body being annularly hollow about said through opening, (b) a hollow container protectively vertically received in said opening formed by said body to be attached to an inner wall formed by said annular body and to be carried by the body, said container and hollow body having thin, annular flexible, correspondingly annularly corrugated walls which have interfering, annular tonge and groove interfit inwardly of the hollow in the float body and outwardly of the hollow in the container, the bottom of the hollow container being substantially flush with the bottom of the hollow body, and (c) tilt sensing means in said hollow container and within said central opening, to be placed in an alarm mode in response to water wave induced tilting of said body, (d) said container including a removable lid attached to the container above the level of the annular body, said tilt sensing means carried by the lid to be accessible in response to removal of the lid from the container, (e) and said tilt sensing means including a pendulum suspended by said lid, and circuitry responsive to swinging of the pendulum to produce an alarm signal, (f) the pendulum surrounded by said annular float body.