Title of Invention

A FLUID LEVEL SENSOR

Abstract

ABSTRACT The instant invention is related to a fluid level sensor, comprising: guide body (10) with a float cavity (53) to guide a float (60) along the guide body (10) during variation of the fluid level, wherein said float (60) makes point contacts with the float cavity (53); reed switch and resistor PCB assembly (70) placed along the guide body (10) for fluid level indication, and magnet (62) mounted onto the float (60) to activate the reed switch (72) and to indicate the fluid level Figurel.

Full Text

FIELD OF INVENTION Fuel level sensor finds application for sensing the level of fuel in a fuel tank. A fuel level sensor comprising grooved aluminium tube, a float (60) with magnet (62), flange (41) with integral connector (40), PCB assembly with Reed Switches and Resistor (70), Bottom cover (05). The float cavity (53) is in the grooved profile of Aluminium tube, which is rigidly fixed to the flange (41). The PCB Assembly (70) along with reed switches (72) and resistor (71) is connected to the terminals in the integral connector (40) in the flange (41). The float (60) moves up and down based on the fuel level, which in turn activates a particular reed switch (72) by magnetic effect between the magnet (62) in the float (60) and the terminals in the reed switch (72). Hence the circuit closes up to the particular reed switch (72). The resistance value against the reed switch (72) is received as the output from the Fuel gauge. OBJECTS OF INVENTION The principle objective of the present invention is to develop a fluid level sensor, comprising: guide body (10) with a float cavity (53) to guide a float (60) along the guide body (10) during variation of the fluid level, wherein said float (60) makes point contacts with the float cavity (53); Another object of the present invention is to develop a reed switch and resistor PCB assembly (70) placed along the guide body (10) for fluid level indication, and magnet (62) mounted onto the float (60) to activate the reed switch (72) and to indicate the fluid level. Another main objective of the present invention is to develop a method to detect fluid level comprises steps of: guiding a float (60) carrying a magnet (62) along a guide body (10) with a float cavity (53), placing reed switch and resistor PCB assembly (70) along the guide body (10), and sliding the float (60) though the float cavity (53) due to variation in fluid level by making point contact (51, 55) with the float cavity (53), and activating the reed switch (72) along the guide body (10) by the float (60) to indicate fluid level. Another main object of the present invention is to develop a method of assembling a fluid level sensor comprises, mounting guide body (10) to a flange comprising integral connector (40), placing a float (60) onto the float cavity (53) and PCB assembly (70) comprising reed switch (72)and resistor (71)in PCB compartment(54), and fixing grommet (06) to the PCB compartment (54) and bottom cover (05) to the guide body (10). STATEMENT OF INVENTION Accordingly the invention provides for a fluid level sensor, comprising: guide body (10) with a float cavity (53) to guide a float (60) along the guide body (10) during variation of the fluid level, wherein said float (60) makes point contacts with the float cavity (53); reed switch and resistor PCB assembly (70) placed along the guide body (10) for fluid level indication, and magnet (62) mounted onto the float (60) to activate the reed switch (72) and to indicate the fluid level; and there is also provide for a method to detect fluid level comprises steps of: guiding a float (60) carrying a magnet(62) along a guide body (10) with a float cavity (53), placing reed switch and resistor PCB assembly (70) along the guide body (10), and sliding the float (60) though the float cavity (53) due to variation in fluid level by making point contact (51,55) with the float cavity (53), and activating the reed switch (72) along the guide body (10) by the float (60) to indicate fluid level; and there is also provide for a method of assembling a fluid level sensor comprises, mounting guide body (10) to a flange comprising integral connector (40), placing a float (60) onto the float cavity (53) and PCB assembly (70) comprising reed switch (72)and resistor (71)in PCB compartiTient(54), and fixing grommet (06) to the PCB compartment (54) and bottom cover (05) to the guide body (10). BRIEF DESCRIPTION OF DRAWINGS Figure 1 shows front perspective view of the Fuel level Sensor Figure 2 shows block drawing of the instant invention with different parts of it Figure 3 shows a reed switch (70) Figure 4 Shows view of the Flange (41) with integral connector (40) of the Fuel level Sensor. Figure 5 Shows perspective view of Housing of the Fuel level Sensor. Figure 6 Shows perspective view of the Float Assembly of the Fuel level Sensor. Figure 7 Shows reed switch and resistor PCB assembly. Figure 8 Shows perspective view of Rubber Sleeve for robust holding of Housing with the Flange (41). Figure 9 shows possible various modification to the flange made thereto without departing from the broader spirit and scope of the invention. Figure 10 shows possible various modification to the fluid level sensor made thereto without departing from the broader spirit and scope of the invention. Figure 11 shows possible various modifications to the Housing of the fuel level sensor made thereto without departing from the broader spirit and scope of the invention. DETAILED DESCRIPTION OF THE INVENTION The primary embodiment of the invention is a fluid level sensor, comprising: a. guide body (10) with a float cavity (53) to guide a float (60) along the guide body (10) during variation of the fluid level, wherein said float (60) makes point contacts with the float cavity (53); b. reed switch and resistor PCB assembly (70) placed along the guide body (10) for fluid level indication, and c. magnet (62) mounted onto the float (60) to activate the reed switch (72) and to indicate the fluid level. In yet another embodiment of the present invention the guide body (10) comprises cavities (50, 52) for suction and return of fluid. In still another embodiment of the present invention the cavities (50, 52) are provided with filters to restrict foreign materials. In still another embodiment of the present invention the guide body (10) is provide with a compartment (54) for placing the reed switch and resistor PCB assembly (70). In still another embodiment of the present invention the guide body (10) is provide with a compartment (54) to reduce guide body material. In still another embodiment of the present invention the guide body (10) is provided with a grommet (06) for both ends of the compartment (54) to restrict fluid entry. In still another embodiment of the present invention the guide body (10) is mounted onto a flange (41) with a rubber sleeve with serrations (80) for robust holding. In still another embodiment of the present invention the guide body (10) is provided with bottom cover (05) to stop the float (60) movement out side the float cavity (53). In still another embodiment of the present invention the bottom cover (05) provides for fluid to flow through it into the cavities (50, 52). In still another embodiment of the present invention the float cavity (53) provides for four point contacts (51, 55). In still another embodiment of the present invention the float (60) provides for two point contacts (63) on its float ribs (61). In still another embodiment of the present invention the float (60) material composition is made compatible with flexi fuel. In still another embodiment of the present invention the float cavity (53) is provided with a plug to restrict the movement of the float (60). Another main embodiment of the present invention a method to detect fluid level comprises steps of a. guiding a float (60) carrying a magnet(62) along a guide body (10) with a float cavity (53), b. placing reed switch and resistor PCB assembly (70) along the guide body (10), and c. sliding the float (60) though the float cavity (53) due to variation in fluid level by making point contact (51, 55) with the float cavity (53), and d. activating the reed switch (72) along the guide body (10) by the float (60) to indicate fluid level. Yet another embodiment of the present invention is restricting the float (60) movement to a predetermined length along the float cavity (53) with a plug. Still another embodiment of the present invention is providing compartment (54) in the guide body (10) to place PCB assembly (70) and to reduce guide body material. Still another embodiment of the present invention is providing cavities (50, 52) for fluid movement in the guide body (10). Another main embodiment of the present invention a method of assembling a fluid level sensor comprises, a) mounting guide body (10) to a flange comprising integral connector (40), b) placing a float (60) onto the float cavity (53) and PCB assembly (70) comprising reed switch (72)and resistor (71)in PCB compartment(54), and c) fixing grommet (06) to the PCB compartment (54) and bottom cover (05) to the guide body (10). Conventional sensing devices for use in sensing the liquid level in fuel tanks include a pickup tube and a return tube positioned adjacent to a float (60). This invention relates to tubular fuel level sensors for use with vehicle fuel tanks such as Car, LCV, HCV, off road vehicle, snowmobiles, etc. An indicating instrument will be used in conjunction with the fuel sensor to read the fuel level in the tank. In accordance with the invention, a liquid level sensor consists an integral housing includes therein a pickup tube which is suction cavity (52), a return tube which is return cavity (50) and a grooved path which is guide cavity (53) for the movement of the float (60). See figure I and figure 2. A sensing board known as PCB assembly (70) is positioned within the cavity in the housing called the compartment (54). The resistor (71) in the PCB (73) reads the fuel level in the tank after the reed switch (72) gets activated. The activation of reed switch (72) is based on the principle of activating a reed switch (72) with another magnet (62) will allow closed operation. It is a further object of the present invention to provide an improved liquid level sensing device that is not subject to wild fluctuations in the liquid level due to movement of the vehicle in rough terrain. It is still another object of the present invention to provide an improved liquid level sensing device that is not likely to be damaged by contact with a tank opening when the sensing device is installed within the tank. Advantages of Reed Switch: • Reed switches are hermetically sealed in glass environment, free from contamination, and are safe to use in harsh industrial and explosive environments. • Reed switches are immune to electrostatic discharge (ESD) and do not require any external ESD protection circuits. • The isolation resistance between the contacts is as high as 1015 ohms, and contact resistance is as low as 50 milliohms. • Reed switches (see figure 3) can directly switch loads as low as a few microwatts without needing external amplification circuits, to as high as 120W. Figure 2 details as listed below No. PART NAME 01. FLANGE (41) WITH INTEGRAL CONNECTOR (40) 02. GIDEBODY(IO) 03. PCB ASSEMBLY (70) 04. FLOAT (60) 05. BOTTOM COVER (05) 06. GROMMET(06) Details of the components used in fuel level sensing Flange (41) Instant invention has a guide body (10) fixed to a flange (41), where the flange (41) is provided with integral connector (40). The purpose of the integral connector (40) to ease the routing of the wiring assembly in the assembly fitment. This connector has connection with wires from the PCB (73) of the PCB assembly (70) internally. See figure 4. Guide body (10): The guide body (10) comprises float cavity (53); cavities (50, 52) and PCB compartment (54). The float cavity (53) is having point's contacts (51, 55) over its surface at 4 places to have friction free movement of the float (60). These four points will have contact with the float (60) thus reducing the amount of friction, wear and tear due to surface contact of the float (60). See figure 5. The cavities (52, 50) are to use as suction and return of the fuel. The suction cavity (52) is usually bigger in size compare to the return cavity (50). Having this cavities (52, 50) will have an advantage of not having separate cavities for suction and return of the fuel in fuel tank. This gives advantage of not have fuel leakage due to the separate holes punched for fuel suction and return. This will also eliminate the time required to punch holes and welding to have air tight in the assembly line. The compartment (54) is the place where the PCB is inserted. Guide ribs are provided to fix the PCB (73) (figure 7) in tact. This compartment (54) is made bigger than required to place the PCB assembly (70) to reduce the weight of the guide body (10) and to reduce the material cost. The contour of the body is designed to have flat surface on one side to have pool-proofing method in the flange (41) assembly. The Flange (41) can also have a provision to allow the return and suction of the fuel to the guide body (10) cavities (52, 50). The guide body (10) is made up of Aluminium or plastic or poly acetal like Delrin based on the requirements of the flexi fuel. Float (60): figure 6 The float (60) is designed to have blind cavity and not a through cavity to fix the iTiagnet(s) (62). This is having an advantage to fix the magnet(s) (62) in the ideal position and more rigid. The float contour is designed to have points contact instead of surface contact with the float cavity (53) to avoid friction/wear in the floating movement. The outer circumference of the float ribs (61) has point contact (63) with the float cavity (53) of the guide body (10). This float (60) is made out of hard rubber sponge using 14 chemical compositions bonding to have compatible with flexi fuel. The composition is varied in such a way that it suits the requirement of the flexi fuel. Further the guide body (10) is provided with a rubber grommet (06) (see figure 2) at bottom and top to restrict the fuel entry into the compartment (54). In addition the guide body (10) is provided with bottom cover (05) to stop the float (60) movement out side the guide body (10). This bottom cover (05) can have a provision to facilitate the fuel movement in the cavities (52, 50). Further the cavities (52, 50) are provided with filters to avoid entry of foreign materials. This invention has the advantage that this will allow to calibrate the instrument with much of easy. Early fuel level sensors had the disadvantage that the calibration is done by dipping the instrument in to the fuel which was difficuk and time consuming. Further after calibration the instrument, it has to be cleaned to remove fuel stains. This is an additional burden during manufacturing. Further the guide body (10) is mounted with flange (41) with a help of a rubber sleeve with serration (80) for robust holding. See figure 8. The entire diameter of the guide body (10) with float (60) is maintained or restricted such that is meets the user needs. Instant invention comprises a suction cavity (52), a return cavity (50) and a float cavity (53). The housing is having a longitudinal axis, where the above said suction cavity (52), return cavity (50) and float cavity (53) are sealed with respect to one another along the longitudinal axis and a float (60) positioned within the float cavity (53) and adapted for movement there along with the help of ribs (61) or grooves. The above said suction (52) and return cavity (50) are substantially parallel to one another and coextensive with one another. The float cavity (53) is substantially parallel to suction cavity (52) and return cavity (50) and is substantially coextensive with suction (52) and return cavity (50). A Flange (41) with integral connector (40) and insert molded terminal. The housing is inserted into the flange (41) rigidly. A Rubber Sleeve introduced in the cavity of the flange (41) where the housing gets inserted. This will helps in robust holding of the housing rigidly within the cavity of the Flange (41). A PCB Assembly (70) positioned within the compartment (54) for sensing the position of the float (60) in the float cavity (53). A set of Reed switches (72) and Resistor (71) are provided which activates the Fuel Level Sensor. A Float Assembly comprises of Magnet (62) for sensing the reed switches (72) and resistors (71). A Grommet (06) is provided at the bottom of the housing to prevent the fuel entry into the cavity in which the PCB Assembly is enclosed. This also comprises of a Bottom Cover (05) to cover the housing at the bottom end and it restricts the fuel entry in to the PCB Cavity area. Float Assembly comprises of Magnet (62) for sensing the reed switches (72) and resistors (71). A Plug is provided to restrict the movement of the float (60) above a certain height from the bottom side. The plug can be provided any were in the float cavity (53) to restrict the float (60) movement to predetermined length of the guide body (10). The float (60) is provided in such a way that only a part of it i.e. the ribs (61) fits within the float cavity (53) and reset remains outside the flat cavity (53). Instant fluid level sensor works even if it is placed inclined to the fluid level. This works perfectly when fitted at an angle instead of exactly perpendicular to the fluid surface. The angle can go upto 30 from perpendicular and still working fine. In this specification, the invention has been described with reference to specific exemplary embodiments thereof It will, however, be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention as set forth in the appended claims. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense. Figure 9, 10 and 11 shows one of the possible modifications as an example for the flange, the fluid level sensor with the modified flange and guide body i.e. housing of fluid level sensor respectively. We claim: 1. A fluid level sensor, comprising; a. guide body (10) with a float cavity (53) to guide a float (60) along the guide body (10) during variation of the fluid level, wherein said float (60) makes point contacts with the float cavity (53); b. reed switch and resistor PCB assembly (70) placed along the guide body (10) for fluid level indication, and c. magnet (62) mounted onto the float (60) to activate the reed switch (72) and to indicate the fluid level. 2. The fluid level sensor as claimed in claim 1, wherein the guide body (10) comprises cavities (50, 52) for suction and return of fluid. 3. The fluid level sensor as claimed in claim 2, wherein the cavities (50, 52) are provided with filters to restrict foreign materials. 4. The fluid level sensor as claimed in claim 1, wherein the guide body (10) is provide with a compartment (54) for placing the reed switch and resistor PCB assembly (70). 5. The fluid level sensor as claimed in claim 1, wherein the guide body (10) is provide with a compartment (54) to reduce guide body material. 6. The fluid level sensor as claimed in claims 1, 4 and 5, wherein the guide body (10) is provided with a grommet (06)for both ends of the compartment (54) to restrict fluid entry. 7. The fluid level sensor as claimed in claim I, wherein the guide body (10) is mounted onto a flange (41) with a rubber sleeve with serrations (80) for robust holding. 8. The fluid level sensor as claimed in claim 1, wherein the guide body (10) is provided with bottom cover (05) to stop the float (60) movement out side the float cavity (53). 9. The fluid level sensor as claimed in claims 2 and 8, wherein the bottom cover (05) provides for fluid to flow through it into the cavities (50, 52). 10. The fluid level sensor as claimed in claim 1, wherein the float cavity (53) provides for four point contacts (51, 55). 11. The fluid level sensor as claimed in claim I, wherein the float (60) provides for two point contacts (63) on its float ribs (61). 12. The fluid level sensor as claimed in claim 1, wherein the float (60) material composition is made compatible with flexi fuel. 13. The fluid level sensor as claimed in claim 1, wherein the float cavity (53) is provided with a plug to restrict the movement of the float (60). 14. A method to detect fluid level comprises steps of: a. guiding a float (60) carrying a magnet(62) along a guide body (10) with a float cavity (53), b. placing reed switch and resistor PCB assembly (70) along the guide body (10), and c. sliding the float (60) though the float cavity (53) due to variation in fluid level by making point contact (51, 55) with the float cavity (53), and d. activating the reed switch (72) along the guide body (10) by the float (60) to indicate fluid level. 15. The method as claimed in claim 14, wherein restricting the float (60) movement to a predetermined length along the float cavity (53) with a plug. 16. The method as claimed in claim 14, wherein providing compartment (54) in the guide body (10) to place PCB assembly (70) and to reduce guide body material. 17. The method as claimed in claim 14, wherein providing cavities (50, 52) for fluid movement in the guide body (10). 18. A method of assembling a fluid level sensor comprises, a) mounting guide body (10) to a flange comprising integral connector (40), b) placing a float (60) onto the float cavity (53) and PCB assembly (70) comprising reed switch (72)and resistor (71)in PCB compartment(54), and c) fixing grommet (06) to the PCB compartment (54) and bottom cover (05) to the guide body (10). 19. The fluid level sensor comprising: a guide body (10) with cavities (50, 52) for suction and return of fluid. 20. A fluid level sensor, a method to detect fluid and method of assembling the fluid level sensor as herein described in the description with exampless and

Documents:

2616-CHE-2007 AMENDED PAGES OF SPECIFICATION 01-02-2012.pdf

2616-CHE-2007 AMENDED PAGES OF SPECIFICATION 05-12-2011.pdf

2616-CHE-2007 AMENDED CLAIMS 01-02-2012.pdf

2616-CHE-2007 AMENDED CLAIMS 05-12-2011.pdf

2616-CHE-2007 CORRESPONDENCE OTHERS 01-02-2012.pdf

2616-CHE-2007 CORRESPONDENCE OTHERS 20-01-2012.pdf

2616-CHE-2007 FORM-1 05-12-2011.pdf

2616-CHE-2007 FORM-13 05-12-2011.pdf

2616-CHE-2007 FORM-3 05-12-2011.pdf

2616-CHE-2007 OTHER PATENT DOCUMENT 05-12-2011.pdf

2616-CHE-2007 POWER OF ATTORNEY 05-12-2011.pdf

2616-che-2007 correspondence others.pdf

2616-CHE-2007 EXAMINATION REPORT REPLY RECEIVED 05-12-2011.pdf

2616-che-2007 form-3 23-06-2010.pdf

2616-che-2007 abstract.pdf

2616-che-2007 claims.pdf

2616-che-2007 description(complete).pdf

2616-che-2007 drawings.pdf

2616-che-2007 form-1.pdf

2616-che-2007 form-18.pdf

2616-che-2007 form-3.pdf

2616-che-2007 form-5.pdf

2616-che-2007-abstract.pdf

2616-che-2007-correspondnece-others.pdf

2616-che-2007-description(provisional).pdf

2616-che-2007-drawings.pdf

2616-che-2007-form 1.pdf

2616-che-2007-form 26.pdf

2616-che-2007-form 3.pdf

2616-che-2007-form 5.pdf