Pressure deactivated torque override coolant cap

• US 6,796,451 B2
• Filed: 07/18/2002
• Issued: 09/28/2004
• Est. Priority Date: 07/18/2002
• Status: Expired due to Fees

• Current Assignee: Stant Manufacturing Incorporated
• Original Assignee: Stant Manufacturing Incorporated
• Inventors: Harris, Robert S.
• Primary Examiner(s): NGO, LIEN M
• Application Number:
  US10/198,243
• Publication Number:
  US 20040011788A1
• Time in Patent Office: 803 Days
• Field of Search: 220/303, 220/330, 220/202, 220/203-2-2, 220/203.01, 220/203.1, 220/203.9, 220/203.06, 220/DIG.32, 220/DIG.33, 220/DIG.17, 220/304, 220/582, 220/86.2, 220/89.1, 220/746, 220/316, 220/251
• US Class Current: 220/203.26
• CPC Class Codes: F01P 11/0238 with overpressure valves or vent valves
• CPC Class Codes: F01P 11/0247 Safety; Locking against opening
• CPC Class Codes: F01P 2011/0266 activated by pressure
• CPC Class Codes: Y10S 220/32 Radiator cap

Abstract

A cap for use on the threaded filler neck of a coolant reservoir, such as an automobile radiator, comprising a cover and main body and including: a means for transmitting torque from the cover to the main body to screw the cap onto the filler neck. The cap but for preventing excess torque from being transmitted. The cap includes a second torque transmission means for unscrewing the cap, which does not limit the torque that can be transmitted. The cap also includes a means for preventing the cap from being unscrewed when the coolant is under pressure; a pressure relief means to prevent the coolant pressure from exceeding a predetermined level; and a vacuum relief means for preventing the coolant pressure from falling below a second predetermined level.

Claims

1. A cap apparatus adapted to be coupled to a threaded filler neck of a coolant reservoir, the cap comprising

a cover;

a main body, the main body including threads for engagement with threads of a filler neck; and

a means for transmitting torque applied to the cover to the main body enabling the threads of the main body to engage the threads of the filler neck,

torque override means for limiting the maximum torque that can be transmitted from the cover to the main body;

means for preventing torque from being transmitted from the cover to the main body to unscrew the main body from the filler neck while the coolant reservoir is pressurized above a first predetermined pressure;

means for preventing the coolant pressure from exceeding an upper predetermined level; and

means for preventing the coolant pressure from falling below a lower predetermined level.

2. A cap apparatus adapted to be coupled to a threaded filler neck of a coolant reservoir, the cap comprising

a cover;

a main body, the main body including threads for engagement with threads of a filler neck; and

means for transmitting torque applied to the cover to the main body that enables the threads of the main body to engage the threads of the filler neck,

torque override means limiting the maximum torque that can be transmitted from the cover to the main body

torque transmission means for permitting torque to be transmitted from the cover to the main body to unscrew the main body from a filler neck comprising fingers descending from the cover top wall, and a series of teeth on the main body upper wall wherein the teeth engage the fingers when an axial force is applied to the cover and where the flanks of the teeth engaged when the cap is unscrewed from filler neck are raked at a low angle;

an override spring disposed between the cover and main body that pulls the cover and main body away toward each other so that the teeth and fingers are only engaged when an axial force is applied to the cover

pressure lock means for preventing torque from being transmitted from the cover to the main body to unscrew the main body from a filler neck while the coolant reservoir is pressurized comprising a valve body;

a valve sealing ring, which forms a seal between the valve body and main body;

a cap retainer attached to the valve body and to the cover;

where the force of coolant pressure acting on the valve body is transmitted through the valve body and cap retainer to the cover, preventing the teeth and fingers from being engaged.

3. A cap apparatus adapted to be coupled to a threaded filler neck of a coolant reservoir, the cap comprising

a cover having a first set of teeth;

a main body having a second set of teeth, the main body including threads for engagement with threads of a filler neck; and

a first spring forcing the first set of teeth and second set of teeth into engagement whereby torque applied to the cover about an axis is transmitted to the main body enabling the threads of the main body to engage the threads of the filler neck,

one of the first and second set of teeth being constructed to limit the maximum torque being transmitted from the first to the second set of teeth when the main body is being screwed onto the filler neck,

a valve body coupled to the cap and movable with respect to the main body,

a surface coupled to the valve body responsive to pressure in the reservoir above a first predetermined level to compress the first spring so that one of the first set of teeth and second set of teeth moves with respect to the other and torque applied to the cover about the axis to unscrew the main body from the filler neck is not transmitted to the main body,

a relief piston movable with respect to the valve body and biased, via a second spring, to maintain pressure in the reservoir, wherein the second spring is responsive to pressure in the reservoir above a second predetermined level to release pressure in the reservoir to atmosphere, and

a vacuum piston movable with respect to the valve body and biased, via a third spring, to maintain pressure in the reservoir, wherein the third spring is responsive to pressure in the reservoir below a third predetermined level to increase pressure in the reservoir from atmosphere.

4. The cap apparatus of claim 3 wherein the one of the first and second set of teeth are constructed of flexible material.

5. The cap apparatus of claim 4 wherein the one of the first and second set of teeth are raked at an angle.

6. The cap apparatus of claim 3 wherein the surface coupled to the valve body separates the first set of teeth and second set of teeth in response to pressure in the reservoir above a first predetermined level.

7. A cap apparatus adapted to be coupled to a threaded filler neck of a coolant reservoir, the cap comprising

a cover having a first set of teeth,

a main body having a second set of teeth, the main body including threads for engagement with threads of a filler neck,

a spring forcing the first set of teeth and second set of teeth into engagement whereby torque applied to the cover about an axis to screw the main body onto the filler neck is transmitted to the main body enabling the threads of the main body to engage the threads of the filler neck,

at least one of the first or second set of teeth being constructed at an angle and flexible to limit the amount of torque transmitted from the cover to the main body to screw the main body onto the filler neck,

a valve body coupled to the cap and movable with respect to the main body,

a surface coupled to the valve body responsive to pressure in the reservoir above a first predetermined level to compress the first spring so that one of the first set of teeth and second set of teeth moves with respect to the other and torque applied to the cover about the axis to unscrew the main body from the filler neck is not transmitted to the main body.

8. A cap apparatus adapted to be coupled to a threaded filler neck of a coolant reservoir, the cap comprising

a cover having a first set of teeth,

a main body having a second set of teeth, the main body including threads for engagement with threads of a filler neck,

a first spring forcing the first set of teeth and second set of teeth into engagement whereby torque applied to the cover about an axis to screw the main body onto the filler neck is transmitted to the main body enabling the threads of the main body to engage the threads of the filler neck,

at least one of the first or second set of teeth being constructed at an angle and flexible to limit the amount of torque transmitted from the cover to the main body to screw the main body onto the filler neck,

a valve body coupled to the cap and movable with respect to the main body, and

a surface coupled to the valve body responsive to pressure in the reservoir above a first predetermined level to separate the first set of teeth from the second set of teeth so that torque applied to the cover about the axis to unscrew the main body from the filler neck is not transmitted to the main body;

a relief piston movable with respect to the valve body and biased, via a second spring, to maintain pressure in the reservoir, wherein the second spring is responsive to pressure in the reservoir above a second predetermined level to release pressure in the reservoir to atmosphere, and

a vacuum piston movable with respect to the valve body and biased, via a third spring, to maintain pressure in the reservoir, wherein the third spring is responsive to pressure in the reservoir below a third predetermined level to increase pressure in the reservoir from atmosphere.