Low-level oil sensor
AssigneeC-K Engineering, Inc.
InventorsHarold Edward McCormick, Mark Murray
Life of this patent
Estimating the term…
Abstract
A low fluid sensor for an internal combustion engine. The sensor includes a base with helically threaded post and a float slidably mounted on the post. The float rotates about the post as it moves longitudinally along it. In the preferred embodiment, eccentric mounting of the assembly along with its lobe shape act in concert with the pitch of the screw threads and fluid viscosity to dampen the buoyant movement of the float against fluid turbulence. At a predetermined level a latch spring on the float contacts an ignition circuit terminal and grounds the engine ignition circuit. A catch holds the float at the pre-determined level, preventing engine starting, so that the sensor may only be reset by addition of fluid and re-insertion of the dipstick.
Claims39
A fluid level sensing apparatus for use in an internal combustion engine, the engine having a fluid reservoir defined in whole or part by a housing wall, comprising:
- a base adapted for mounting in the fluid reservoir, the base having a sidewall and a helically threaded post;
- a terminal contact connected to a circuit;
- a float having a guide sleeve with internal projections and a flexible electrically conductive element attached to its outer surface;
- the float being buoyant and slidably mounted upon the threaded post such that the float rotates about the post in one direction as it moves along the post in response to an increase in fluid level in the reservoir and rotates in the other direction as it moves along the post in response to a decrease in fluid level in the reservoir;
- and
- wherein when the float reaches a pre-determined level on the post, the rotational motion of the float moves the electrically conductive element into contact with the terminal contact.
A fluid level sensing apparatus for use in an internal combustion engine, the engine having a fluid reservoir defined in whole or part by a housing wall, comprising:
- a base mounted in the fluid reservoir, the base having a sidewall and a helically threaded post:
- a terminal contact connected to a circuit;
- a float having a guide sleeve with internal projections and a flexible electrically conductive element attached to it;
- the float being buoyant and slidably mounted upon the threaded post such that the float rotates about the post in one direction as it moves along the post in response to an increase in fluid level in the reservoir and rotates in the other direction as it moves along the post in response to a decrease in fluid level in the reservoir;
- the electrically conductive element having a first end and a second end and the first end of the element remains in contact with the housing wall of the fluid reservoir as the float rotates about the post;
- and
- wherein when the float reaches a pre-determined level on the post, the second end of the element contacts the terminal contact.
A fluid level sensing apparatus for use in an internal combustion engine, the engine having a fluid reservoir, comprising:
- a base adapted for mounting in the fluid reservoir, the base having a floor, a sidewall encompassing the floor, a first terminal contact, a second terminal contact and a helically threaded post mounted on the floor of the base;
- a float having a guide sleeve with internal projections and a flexible electrically conductive element, the element having a first end and a second end;
- the float being buoyant and slidably mounted upon the threaded post such that the float rotates about the post in one direction as it moves along the post in response to an increase in fluid level in the reservoir and rotates in the other direction as it moves along the post in response to a decrease in fluid level in the reservoir;
- and
- wherein when the float reaches a pre-determined level on the post, the first end of the element contacts the first terminal contact and the second end of the element contacts the second terminal contact.
A fluid level sensing apparatus comprising:
- a base adapted for mounting in a fluid reservoir, the base having a sidewall, and a helically threaded post;
- a float having a sleeve with internal projections and adapted to receive an electrically conductive element on its outer surface;
- and
- the float being buoyant and slidably mounted upon the threaded post such that the float rotates about the post in one direction as it moves along the post in response to increase in fluid level in the reservoir and rotates in the other direction as it moves along the post in response to a decrease in fluid level in the reservoir.
A fluid level sensing apparatus comprising:
- a base adapted for mounting in a fluid reservoir, the base having a floor, a sidewall encompassing the floor, and a helically threaded post mounted on the floor of the base;
- a float having a sleeve with internal projections and adapted to receive a flexible electrically conductive element on its outer surface;
- and
- the float being buoyant and slidably mounted upon the threaded post such that the float rotates about the post in one direction as it moves along the post in response to increase in fluid level in the reservoir and rotates in the other direction as it moves along the post in response to a decrease in fluid level in the reservoir.
A fluid level sensing apparatus for use in an internal combustion engine, the engine having a fluid reservoir and an ignition circuit, comprising:
- a base mounted in the fluid reservoir. the base having a wall segment, a helically threaded post;
- a terminal contact adapted for connection to the ignition circuit;
- a float having a sleeve with internal projections and a a flexible electrically conductive element having a first end and a second end;
- the float slidably mounted upon the threaded post such that the float rotates about the post in one direction as it moves along the post in response to increase in fluid level in the reservoir and rotates in the other direction as it moves along the post in response to a decrease in fluid level in the reservoir;
- and
- wherein when the float reaches a pre-determined level on the post, the rotational motion of the float moves the electrically conductive element into contact with the terminal contact.
A fluid level sensing apparatus for use in an internal combustion engine, the engine having a Fluid reservoir, comprising:
- a base mounted in the fluid reservoir and having a helically threaded post;
- a terminal contact adapted for connection to a circuit;
- a float having a guide sleeve with internal projections;
- a flexible electrically conductive element having a first end and a second end;
- the float being buoyant and slidably mounted upon the threaded post such that the float rotates about the post in one direction as it moves along the post in response to an increase in fluid level in the reservoir and rotates in the other direction as it moves along the post in response to a decrease in fluid level in the reservoir;
- and
- wherein when the float reaches a pre-determined level on the post, the rotational motion of the float moves the electrically conductive element into contact with the terminal contact.
A method of shutting down an engine, the engine having an ignition circuit and a fluid reservoir, the method comprising:
- providing a base mounted in the fluid reservoir, the base having a sidewall, a helically threaded post and a terminal contact connected to the ignition circuit;
- providing a buoyant float, the buoyant float having a guide sleeve with internal projections and being slidably mounted upon the threaded post such that the float rotates about the post in one direction as it moves along the post in response to increase in fluid level in the reservoir and rotates in the other direction as it moves along the post in response to a decrease in fluid level in the reservoir;
- providing a flexible electrically conductive element, the element having a first end and a second end;
- and
- grounding the ignition circuit by moving the element into contact with the terminal contact using only the buoyancy-based rotational motion of the float to move the element.
A method of alerting an engine operator to a low fluid condition in the engine, the engine having a alarm circuit and a fluid reservoir, the method comprising:
- providing a base mounted in the fluid reservoir, the base having a sidewall, a helically threaded post and a terminal contact connected to the alarm circuit;
- providing a buoyant float, the buoyant float having a guide sleeve with internal projections and being slidably mounted upon the threaded post such that the float rotates about the post in one direction as it moves along the post in response to increase in fluid level in the reservoir and rotates in the other direction as it moves along the post in response to a decrease in fluid level in the reservoir;
- providing a flexible electrically conductive element, the element having a first end and a second end;
- and
- activating the alarm circuit by moving the element into contact with the terminal contact using only the buoyancy-based rotational motion of the float to move the element.
A method of grounding an engine ignition circuit in response to a low fluid condition and then restoring the ignition circuit's ignition capability, the engine having an ignition circuit, a fluid reservoir, a dipstick tube and dipstick, the method comprising:
- providing a base mounted in the fluid reservoir, the base having a sidewall, a helically threaded post and a terminal contact connected to the ignition circuit;
- providing a buoyant float, the buoyant float having a guide sleeve with internal projections and having a flexible electrically conductive element tangentially attached to it;
- the buoyant float being slidably mounted upon the threaded post such that the float rotates about the post in one direction as it moves along the post in response to increase in fluid level in the reservoir and rotates in the other direction as it moves along the post in response to a decrease in fluid level in the reservoir;
- providing a second terminal contact leading to electrical ground;
- rotating the float using only the buoyancy forces from the fluid in the reservoir such that at a pre-determined level of fluid in the reservoir the element makes simultaneous contact with the first terminal contact and the second terminal contact;
- restraining the float from further rotational movement once the element contacts the contact terminals;
- and
- extracting the dipstick from the dipstick tube, adding fluid to the fluid reservoir and re-inserting the dipstick in the dipstick tube.
Dependencies are inferred from the claim text.