Patent ID: 7230540

Claim:
A liquid level alarm comprising: a weight; a floating box being hollow and having a top; a bottom; a top recess defined in the top and having an inner surface; a bottom recess defined in the bottom; a passage defined in the floating box between the top recess and the bottom recess; a top cover mounted hermetically on the top and covering the top recess; a bottom cover mounted over the bottom recess and having a through hole defined through the bottom cover; and a slide mounted slidably in the passage; an alarm circuit mounted in the top recess in the floating box and having two contacts; an alarm element connected to the contacts; a switch connected to the slide in the passage in the floating box and selectively contacting the contacts to activate the alarm element; and a spring connected to the top cover on the floating box and the switch and supplying a resilient force to hold the switch open; and a cord having a bottom end connected to the weight and a top end extending through the through hole in the bottom cover and the bottom recess in the floating box and connected to the slide.