Liquid level alarm system

• US 5,945,913 A
• Filed: 05/19/1997
• Issued: 08/31/1999
• Est. Priority Date: 12/26/1995
• Status: Expired due to Fees

• Current Assignee: Daniel J. Gallagher
• Original Assignee: Daniel J. Gallagher
• Inventors: Gallagher, Daniel J.
• Primary Examiner(s): Hofsass, Jeffery A.
• Assistant Examiner(s): TWEEL JR, JOHN ALEXANDER
• Application Number:
  US08/858,110
• Time in Patent Office: 834 Days
• Field of Search: 340/618, 340/623, 340/624, 73/307, 73/308, 73/319, 116/110, 116/228, 137/558, 251/309, 200/61.04, 200/84 B, 200/84 R
• US Class Current: 340/618
• CPC Class Codes: G01F 23/44 using electrically actuated indicating means
• CPC Class Codes: G01F 23/68 using electrically actuated indicating means

Abstract

A liquid level alarm system is activated when liquid in a container falls below a predetermined level. The system contains an alarm located outside the container. The alarm is electrically connected to a switching device. The switching device may have a push-down button located on the top, an "on-off" switch located on the side, or a sliding switch located on the side. When the switch is pushed down, the switching device activates the alarm. In one embodiment, the container has a vertically positioned rod adjacent the switching device. There is a float slidably connected to the rod by a connecting rod and hook. The float rises and falls with the level of the liquid. On the side of the rod opposite the float there is a switch contact which makes contact with the switch when the level of the liquid falls below a predetermined level and the float is no longer supported by the liquid. In another embodiment, a float is positioned on tracks so that the switch will be forced down by the float when the liquid level falls below a predetermined point. The tracks contain slots allowing rollers attached to the float to freely rise and fall with the liquid level while maintaining its position relative to the switch. The switching device may be electrically connected to a motor which, when activated, changes a valve in an inlet pipe from the open position to the closed position.

Claims

1. An alarm system for use in a container having a top having inner and outer surfaces, a bottom having inner and outer surfaces, and at least one wall having an inner and outer surface, which container contains a liquid having a surface level which fluctuates between a predetermined high point and a predetermined low point;

said system comprising;

(a) an alarm means to be positioned outside the container;

(b) A pair of tracks having an upper end and a lower end to be positioned vertically within the container and extending at least between a point near the predetermined high point of the liquid and a point near the predetermined low point of the liquid;

(c) an electrical switching means to be positioned inside the container near the predetermined low point of the liquid surface, said switching means having a top, a bottom, and at least one side, the top or the side of said switching means having a switch, which switch is capable of being pushed vertically downwardly to actuate an activating mechanism contained within the switching means which, in turn, activates the alarm;

(d) a connecting means for electrically connecting the switching means and the alarm means; and

(e) a float suitable for floating on the surface of the liquid, said float having rollers attached thereto, which rollers fit in the tracks allowing the float to move vertically as the liquid rises and falls yet maintain its position relative to the switching means, said float being capable of depressing the switch when the level of the liquid falls to a point which is sufficiently low that the weight of the float presses down upon the switch, the spatial correspondence between the float and the switch being such that the float comes in direct contact with the switch when the surface level of the liquid falls to the predetermined low point.

2. A combination comprising a container and the alarm system defined in claim 1.

3. The combination of claim 2, wherein the switch is on top of the switching means.

4. The combination of claim 2, wherein the switch is on a side of the switching means.

5. The combination of claim 2, wherein the alarm system is part of a unified security system.

6. The combination of claim 2, wherein the alarm comprises an audible indicator.

7. The combination of claim 2, wherein the container is a commode reservoir, the alarm means is attached to the commode, and the connecting means passes from outside the reservoir to inside the reservoir between the top and a side of the reservoir.

8. The combination of claim 2, wherein the float is spherical in shape.

9. The combination of claim 2, wherein the container has an inlet pipe;

an electrical connecting means connects the switching means to a motor containing a rotatable shaft; and

the rotatable shaft is connected to a valve in the inlet pipe, which valve has an open and a closed position, so that when the switching means is activated the valve in the inlet pipe is moved from the open position to the closed position.

10. The combination of claim 9, wherein the valve is a petcock valve.