Liquid level alarm for remotely indicating when less than a predetermined quantity of fuel oil remains in a storage tank and method for installing the same

In a rising stem fuel indicating gauge used to measure the quantity of liquid fuel remaining within a fuel storage tank, said indicating gauge being of the type including a tube for housing a level-indicating element on a shaft within said tube, and indicating markings on said tube for determining the quantity of fuel within said fuel storage tank corresponding to the level of said indicating element in said tube;

• the improvement comprising;
• a magnetic element carried on said level-indicating element;
• a magnetically actuated switch mounted to said tube, said switch being selected so that it is magnetically actuated by said magnetic element carried on said level indicating element when said magnetic element descends in said tube to less than a predetermined distance away from said switch, said switch being mounted on said tube in such position that actuation of said switch by said magnetic element indicates that no more than a predetermined quantity of fuel remains within said fuel storage tank;
• a warning light electrically coupled to said magnetically actuated switch and positioned remotely from said fuel storage tank, and
• a sleeve longitudinally arranged within said tube and around said shaft and supported at one end by the base of said gauge, said sleeve being of an outside diameter less than the inside diameter of said tube and being of an inside diameter less than said level-indicating element and greater than said shaft in said tube, said sleeve being of a length sufficient to stop said level-indicating element from descending within said tube below the level at which said magnetically actuated switch is positioned so that said magnetic element carried on said level-indicating element will be maintained substantially in alignment with said switch for continuous actuation of said alarm when said fuel in said storage tank is less than the predetermined quantity.

A method of providing an alarm for an existing rising stem fuel indicating gauge used to measure the quantity of fuel remaining within a fuel storage tank, said indicating gauge being of the type including a tube for housing a level-indicating element on a shaft within said tube, and indicating markings on said tube for determining the quantity of fuel remaining in said storage tank corresponding to the level of said indicating element in said tube,

• the steps of said method including:
• positioning a magnetic element on said level-indicating element;
• mounting a magnetically actuated switch on said tube, said switch being selected so that it is magnetically actuated by said magnetic element when said magnetic element descends in said tube to less than a predetermined distance from said switch, said switch being mounted to said tube in such position that actuation of said switch by said magnetic element indicates that no more than a predetermined quantity of fuel remains in said storage tank, and
• coupling an alarm to said magnetically actuated switch for actuation of said alarm upon actuation of said switch;
• whereby actuation of said alarm provides indication that no more than said predetermined quantity of fuel remains within said fuel storage tank.