Fail-safe thermostat for vehicular cooling systems
First Claim
1. A fail-safe thermostat for automotive vehicle cooling systems having a junction joining a coolant passageway for internal coolant circulation, and a radiator passageway, comprising:
- a housing mounted in the junction and including an apertured outer structure;
an interior valve mounted in the housing in the path of coolant moving between the coolant passageway and the radiator passageway, the interior valve having a fixed outer peripheral segment and an inner segment movable relative thereto;
thermally responsive actuator means mounted in the housing and including cylinder means slidably mounted relative to the housing and a central rod within the cylinder means and coupled to the housing, the cylinder means being coupled to the inner valve segment and controlling the interior valve segment position by moving in a first direction when coolant temperature increases;
spring means coupled between the housing and the inner valve segment to oppose movement of the inner valve segment; and
fusible alloy means disposed to couple the cylinder means temporarily to the inner valve segment and releasing the coupling when melted, to enable the spring means to drive the inner valve segment past the outer segment in a direction opposite the first direction to open a flow path through the housing between the radiator passageway and the coolant passageway.
2 Assignments
0 Petitions
Accused Products
Abstract
A fail-safe thermostat for vehicular cooling systems is positioned in a junction leading to an internal coolant passageway, a radiator passageway and a bypass passageway. An open housing seated in the junction supports a fixed central rod extending into the wax filled interior of a movable cylindrical member which controls the position of the interior segment of a main valve. Expansion of the wax forces the cylindrical member in a first direction against a compression spring. Fusible alloy is disposed in the coupling between the cylindrical member and the main valve, and melts at a specific temperature range in excess of the normal range. When this occurs the coupling is released in such a way that the spring forces the valve member to a second limit position opposite to the direction of expansion. A bypass closure member at one end of the cylindrical member may be used to close the bypass passageway concurrently with increased temperature.
67 Citations
16 Claims
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1. A fail-safe thermostat for automotive vehicle cooling systems having a junction joining a coolant passageway for internal coolant circulation, and a radiator passageway, comprising:
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a housing mounted in the junction and including an apertured outer structure; an interior valve mounted in the housing in the path of coolant moving between the coolant passageway and the radiator passageway, the interior valve having a fixed outer peripheral segment and an inner segment movable relative thereto; thermally responsive actuator means mounted in the housing and including cylinder means slidably mounted relative to the housing and a central rod within the cylinder means and coupled to the housing, the cylinder means being coupled to the inner valve segment and controlling the interior valve segment position by moving in a first direction when coolant temperature increases; spring means coupled between the housing and the inner valve segment to oppose movement of the inner valve segment; and fusible alloy means disposed to couple the cylinder means temporarily to the inner valve segment and releasing the coupling when melted, to enable the spring means to drive the inner valve segment past the outer segment in a direction opposite the first direction to open a flow path through the housing between the radiator passageway and the coolant passageway. - View Dependent Claims (2, 3, 4, 5)
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6. A vehicular thermostat for controlling flow of coolant in a passageway between a coolant pump and a radiator comprising:
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cylindrical means defining a central interior chamber having an open end; central rod means extending into the interior chamber through the open end and having a free end adjacent the passageway; seal means within the cylindrical means slidably engaged to the central rod means and closing the open end of the interior chamber; a temperature responsive medium filling the interior chamber, said medium volumetrically changing with temperature to act against the central rod means and exert force on the cylinder means to displace the same axially in a first direction; valve means coupled to the cylindrical means and movable therewith, the coupling including a temperature responsive alloy material; thermostat housing means mountable in fixed relation to the passageway and coupled to the free end of the central rod to hold the central rod in fixed relation; and means including a spring means disposed between the valve means and the thermostat housing means for (1) opposing movement of the valve means in the first direction and (2) shifting the position of the valve means if the coolant exceeds a predetermined temperature and melts the temperature responsive alloy material. - View Dependent Claims (7, 8, 9, 10)
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11. A fail-safe thermostat for automotive vehicles comprising:
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a cylindrical body having an interior chamber; flow valve means coupled to the cylindrical body, the flow valve means including a fixed ring outer portion and a movable disk central portion; central rod means coupled to the fixed outer portion and extending into the interior chamber; temperature responsive wax means within the interior chamber and expanding under normal temperature conditions to urge the cylindrical body in a first direction by exerting force against the central rod means; means including fusible alloy means coupling the movable disk central portion of the flow valve means to the cylindrical body to move the cylindrical body and the movable disk portion in a first direction in response to increasing temperature, the fusible alloy being positioned to release the movable disk from force exerted against the central rod means by the wax means upon melting when a predetermined temperature above the normal operating temperature is reached; and spring means coupled between the fixed outer portion and the movable disk portion to resiliently oppose movement in the first direction and to force the movable disk in a second direction to open the valve when the fusible alloy means melts. - View Dependent Claims (12, 13)
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14. A fail-safe thermostat for coolant flow control in the flow control junction of a vehicular cooling system having a radiator passageway leading to at least one engine block coolant passageway transverse thereto and an aligned bypass passageway, comprising:
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cylindrical sleeve means defining a central chamber, the cylindrical sleeve means being positioned in the flow control junction and having a first end extending toward the bypass junction; an outer ring valve member mounted in the flow control junction to partially block flow between the radiator passageway and engine block passageway; first support means at the bypass side coupling the outer ring valve member to the cylindrical sleeve means at an intermediate region thereon; an inner disk valve member coupled to the cylindrical sleeve means and positioned within the outer ring valve member to block flow between the radiator passageway and engine block passageway; a central rod extending into the central chamber of the cylindrical sleeve means from a second end adjacent the radiator passageway; second support means on the radiator passageway side coupling the central rod to the outer ring valve member; means slidably sealing the central rod within the cylindrical sleeve means to define a closed central chamber; thermally responsive means filling the closed central chamber about the central rod to exert axial force thereon in response to coolant temperature such as to slide the cylindrical sleeve means and the inner disk valve member in the direction toward the bypass passageway; first compression spring means disposed between the inner disk valve member and the first support means to resiliently oppose motion of the inner disk valve member toward the bypass passageway; thermally responsive fusible alloy means coupled between the inner disk valve member and the cylindrical sleeve means to release the inner disk valve means from the central rod at a predetermined temperature above normal operating temperature such that the inner disk valve means is urged away from the bypass passageway by the first compression spring means, to open the valve; bypass valve means slidably positioned on the first end of the cylindrical sleeve means for selectively closing the bypass passageway; and second compression spring means coupled between the first support means and the bypass valve means for resiliently urging the bypass valve means toward the bypass passageway. - View Dependent Claims (15, 16)
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Specification