Pressure regulator for engine cooling system

A cooling system apparatus comprising

• a coolant tank formed to include an interior region and a passageway opening into the intenor region,
• an overflow tank coupled to coolant tank through the passageway and formed to include an interior region communicating with the passageway,
• a pressure regulator arranged normally to block flow of fluid between the interior regions of the coolant and overflow tanks via the passageway, the pressure regulator including a pressure-relief valve member, a biasing spring associated with the pressure-relief valve member, and a compression controller mounted for movement relative to the overflow tank to vary biasing force applied by the biasing spring to maintain the pressure-relief valve member in a closed position blocking flow of fluid between the interior regions of the coolant and overflow tanks via the passageway, and
• wherein the overflow tank includes internal threads and the compression controller includes external threads configured to mate with the internal threads to support the compression controller for rotation about and linear motion along an axis relative to the overflow tank in a first direction to compress the biasing spring so as to greaten the biasing force applied by the biasing spring to maintain the pressure-relief valve member in the closed position and in a second direction to decompress the biasing spring so as to lessen the biasing force applied by the biasing spring to maintain the pressure-relief valve member in the closed position.

A cooling system apparatus comprising

• a coolant tank formed to include an interior region and a passageway opening into the interior region,
• an overflow tank coupled to coolant tank through the passageway and formed to include an interior region communicating with the passageway,
• a pressure regulator arranged normally to block flow of fluid between the interior regions of the coolant and overflow tanks via the passageway, the pressure regulator including a pressure-relief valve member, a biasing spring associated with the pressure-relief valve member, and a compression controller mounted for movement relative to the overflow tank to vary biasing force applied by the biasing spring to maintain the pressure-relief valve member in a closed position blocking flow of fluid between the interior regions of the coolant and overflow tanks via the passageway, and
• wherein the coolant tank includes an outer wail formed to include the passageway therein, the overflow tank is coupled to the coolant tank to cause the interior region of the coolant tank to lie on a first side of the outer wall and the interior region of the overflow tank to lie on an opposite second side of the outer wall, and the biasing spring is located in the interior region of the overflow tank and arranged normally to apply a biasing force to urge the pressure-relief valve member to engage the opposite second side of the outer wall to block flow of fluid into the interior region of the overflow tank from the interior region of the coolant tank via the passageway.

A cooling system apparatus comprising

• a coolant tank formed to include an interior region and a passageway opening into the interior region,
• an overflow tank coupled to coolant tank through the passageway and formed to include an interior region communicating with the passageway,
• a pressure regulator arranged normally to block flow of fluid between the interior regions of the coolant and overflow tanks via the passageway, the pressure regulator including a pressure-relief valve member, a biasing spring associated with the pressure-relief valve member, and a compression controller mounted for movement relative to the overflow tank to vary biasing force applied by the biasing spring to maintain the pressure-relief valve member in a closed position blocking flow of fluid between the interior regions of the coolant and overflow tanks via the passageway, and
• wherein the compression controller includes a spring mount and a drive shaft coupled to the spring mount and arranged to extend away from the spring mount and through an aperture formed in the overflow tank and the biasing spring is interposed between the spring mount and the pressure-relief valve member.

A cooling system apparatus comprising a coolant tank,

• an overflow tank arranged to receive fluid discharged from the coolant tank,
• a pressure-relief valve member in the overflow tank and arranged normally to assume a closed position blocking flow of fluid discharged from the coolant tank into the overflow tank,
• a biasing spring in the overflow tank and arranged normally to apply a biasing force to urge the pressure-relief valve member to assume the closed position, and
• means for varying the biasing force applied by the biasing spring to one of lessen the biasing force applied by the biasing spring to maintain the pressure-relief valve member in the closed position so that a first pressure of fluid in the coolant tank is sufficient to move the pressure-relief valve member against the biasing force of the biasing spring to assume an opened position allowing flow of fluid from the coolant tank into the overflow tank and greaten the biasing force applied by the biasing spring to maintain the pressure-relief valve member in the closed position so that a greater second pressure of fluid in the coolant tank must be extant to move the pressure-relief valve member against the biasing force of the biasing spring to assume an opened position allowing flow of fluid from the coolant tank into the overflow tank.

A cooling system apparatus comprising a coolant tank,

• an overflow tank arranged to receive fluid discharged from the coolant tank,
• a pressure-relief valve member arranged normally to assume a closed position blocking flow of fluid discharged from the coolant tank into the overflow tank,
• a biasing spring arranged normally to apply a biasing force to urge the pressure-relief valve member to assume the closed position,
• a drive shaft mounted for controlled movement in a bore formed in the overflow tank, and
• a spring mount coupled to the drive shaft, located in the overflow tank, and arranged to engage an outer end of the biasing spring to lessen the biasing force applied by the biasing spring to maintain the pressure-relief valve member in the closed position in response to movement of the drive shaft in a first direction in the bore toward the coolant tank and to greaten the biasing force applied by the biasing spring to maintain the pressure-relief valve member in the closed position in response to movement of the drive shaft in an opposite second direction in the bore away from the coolant tank.

A cooling system apparatus comprising

• a coolant tank,
• an overflow tank arranged to receive fluid discharged from the coolant tank, the overflow tank including a top wall and a stand-off coupled to the top wall and arranged to extend into an interior region formed in the overflow tank,
• a pressure-relief valve member located in the interior region of the overflow tank and arranged normally to assume a closed position blocking flow of fluid discharged from the coolant tank into the overflow tank, and
• a biasing spring located in the interior region of the overflow tank and arranged to engage the stand-off normally to apply a biasing force to urge the pressure-relief valve member to assume the closed position.