FLOAT OPERATED SIGNALLING DEVICE

• US 3,710,613 A
• Filed: 04/26/1971
• Issued: 01/16/1973
• Est. Priority Date: 05/08/1970
• Status: Expired due to Term

• Current Assignee: Bestobell Limited
• Original Assignee: Ernest Albert Morrison, Robert Innes
• Inventors: Innes, Robert, Morrison, Ernest Albert
• Primary Examiner(s): Prince, Louis R.
• Assistant Examiner(s): Roskos, Joseph W.
• Application Number:
  US05/137,444
• Time in Patent Office: 631 Days
• Field of Search: 73/1R,305,307,314,319,322.5,313,DIG.5 340/410
• US Class Current: 335/205
• CPC Class Codes: F22B 37/425 Feed-water supply alarm devices using floats
• CPC Class Codes: F22B 37/78 Adaptations or mounting of level indicators level indicators per se G01F
• CPC Class Codes: G01F 23/30 by floats
• CPC Class Codes: G01F 23/56 using elements rigidly fixed to, and rectilinearly moving with, the floats as transmission elements
• CPC Class Codes: G01F 25/22 Checking proper indicating of discrete level by floats
• CPC Class Codes: Y10S 73/05 Liquid levels with magnetic transmission

Abstract

The invention is concerned with a float operated signalling device in which a magnet follows the movement of a float in a closed liquid container, the magnet reciprocating in a non magnetic tube through which it operates signal controls. An auxiliary liquid supply is connected to the tube for providing a temporary hydraulic pressure differential across the piston or a part attached to the piston so that the float is dunked below the liquid level and the magnet operates the signal controls for test purposes.

Claims

1. In a float operating signalling device of the kind comprising a liquid container, a non-magnetic tube which is arranged to be in communication with said liquid container, a float member in said liquid container, float responsive means including a magnet, which float responsive means in reciprocable in said tube and which is coupled to and follows movement of said float member, and signal controls on the outside of said tube wall and actuable upon movement of said magnet, the improvement according to which means are provided for supplying liquid to the end of said tube on the side of said magnet remote from said float member, and said float responsive means has a clearance from said tube wall sufficient to permit said float member to float freely during the normal operation of said device but small enough to cause said float responsive means to act as a piston when liquid is supplied under pressure through said end of said tube and move said magnet in response to said pressure along said tube against the buoyancy of said float member to test said device.

2. A device according to claim 1, wherein said float responsive means includes a part attached directly to said magnet.

3. A device according to claim 2, wherein said part attached directly to said magnet is a disc attached to the end of said magnet Remote from said float member.

4. A device according to claim 1, wherein said tube is upright and said magnet is attached to the upper end of a stem to the lower end of which said float member is attached.

5. A device according to claim 4, wherein said float member moves upwards and downwards within a cage which is arranged to be fixed in position and said tube and signal controls are mounted on a removable closure for the upper end of said cage.

6. A device according to claim 1, wherein there are two sets of signal controls which are actuated individually when said magnet is at different positions along said tube.

7. A liquid container installation comprising a liquid container fitted with a signalling device according to claim 1, and a conduit which is connected to said end of said tube, said conduit being connected to a source of liquid under pressure and incorporating a check valve.

8. An installation according to claim 7, wherein said conduit is a branch from a main supply line for said container.

9. An installation according to claim 8, wherein said main supply line incorporates a non return check valve downstream of said conduit branch and a throttle between said check valve and said conduit branch.