System for controlling the level of the liquid contained in a LPG tank or the like

• US 6,490,922 B1
• Filed: 12/10/1999
• Issued: 12/10/2002
• Est. Priority Date: 03/31/1999
• Status: Expired due to Fees

• Current Assignee: Geofin S.R.L.
• Original Assignee: Areagas S.r.l.
• Inventors: Galeotti, Fabrizio, Sprea, Dino
• Primary Examiner(s): Williams, Hezron
• Assistant Examiner(s): CYGAN, MICHAEL T
• Application Number:
  US09/458,773
• Time in Patent Office: 1,096 Days
• Field of Search: 733/08, 733/13, 733/17, 73D/IG.5, 340/870.02, 340/870.16
• US Class Current: 73/313
• CPC Class Codes: G01F 23/38 using magnetically actuated indicating means
• CPC Class Codes: G01F 23/80 Arrangements for signal processing
• CPC Class Codes: Y10S 73/05 Liquid levels with magnetic transmission

Abstract

A system detects the level of a liquid contained in a liquid gas tank or the like by using a magnet.

This system is mounted on a tank (1). The tank is usually provided with a mechanical level indicator. The mechanical level indicator transmits a certain angular rotation to a stem (2). The upper end of the stem is connected with a magnet. The magnet is placed within a flanged body (3) which is fixed on the tank surface.

A casing (4) including a transmitting apparatus (6), coupled with at least a magnetic reader (5) is arranged out of the tank (1) and over the magnet which is placed within the flanged body (3).

On the basis of the angular displacement of the magnet, the transmitting apparatus and magnetic reader translate the filling level of the tank in signals to be transmitted to suitable receiving devices.

Claims

1. A system for detecting a level of liquid in an LPG tank (1), comprising:

a stem (2) mounted for rotation in the tank, an angular position of the stem corresponding to a level of liquid in the tank, the stem having an upper end with a permanent magnet for creating a magnetic field which varies with rotation of the stem, variations of the magnetic field corresponding to angular positions of the stem;

a flanged body (3) connected to the tank, the upper end of the stem with the magnet, extending into the flanged body;

an electronic sensor (5) adjacent the flanged body (3) but outside the tank, the sensor being in the magnetic field and including a disk and four Hall-effect sensor elements equally circumferentially spaced around 360 degrees and around the magnetic field and mounted on the disk, each sensor element generating a current that is proportional to the variations in the magnetic field adjacent the sensor element so that the currents of all the sensor elements together create digital logic information corresponding to the angular position of the stem and thus to the level of liquid in the tank, each sensor element being a binary sensor element which is either on or off so that the digital logic information is binary information;

a radio transmitter (6) connected to the sensor (5) for transmitting the digital logic information to a remote location, the transmitter extending vertically from the disk in the container;

a container (4) over the sensor and the transmitter and outside the tank for protecting the sensor and the transmitter; and

a battery in the container for powering the electronic sensor and the transmitter.

2. A system according to claim 1, wherein the container is made of plastic, and the flanged body includes a pair of connectors for connecting the flanged body to the tank.

3. A system according to claim 1, including a window in the container for viewing into the container, and wherein the container includes a base which separates the upper end of the stem from the sensor.

4. A system for controlling the level of gas or liquid contained in a LPG tank, the system comprising:

a flanged body (3) connected to the tank;

a container (4) mounter to the tank;

an indication magnet mounted to the flanged body for generating a magnetic field in the container;

an electronic sensor (5) in the container and adjacent the flanged body (3) but outside the tank, the sensor being in the magnetic field and including four Hall-effect sensor elements equally circumferentially spaced around 360 degrees and around the magnetic field, the sensor including a disk on which the four sensor elements are mounted and each sensor element generating a current that is proportional to the variations in the magnetic field adjacent the sensor element so that the currents of all the sensor elements together create digital logic information corresponding to the angular position of the stem and thus to the level of liquid in the tank, each sensor element being a binary sensor element which is either on or off so that the digital logic information is binary information;

a radio transmitter (6) connected to the sensor (5) for transmitting the digital logic information to a remote location, the transmitter extending vertically from the disk in the container; and

a battery in the container and connected to the sensor and the transmitter, for powering the sensor and the transmitter.