Internal combustion engine coolant system, thermostat therefor and methods of making the same

Claim 2

In an internal combustion engine coolant system having a radiator for receiving coolant into an inlet thereof from an outlet of said engine through a thermostat disposed intermediate said outlet of said engine and said inlet of said radiator and having a coolant pump for circulating said coolant through said engine from an inlet of said engine to said outlet thereof, said pump having a first inlet interconnected to said outlet of said engine upstream of said thermostat and a second inlet interconnected to the outlet of said radiator while having its outlet interconnected to said inlet of said engine, said thermostat having a vent valve means carried by the main valve member thereof for venting air from said outlet of said engine to said inlet of said radiator when said main valve member of said thermostat is in a closed condition against the main valve seat thereof and said system is being filled with coolant that is being introduced into said radiator and for preventing coolant flow through said vent valve means when said pump is circulating said coolant and said main valve member of said thermostat is in a closed condition against said main valve seat, the improvement wherein said vent valve means comprises a vent opening through said main valve member and a flexible vent valve member for opening and closing said vent opening, said flexible vent valve member normally being held in spaced relation from said vent opening and being adapted to be flexed against said vent opening to close said vent opening by said coolant being circulated by said pump.

Claim 3

A system as set forth in claim 1 wherein said thermostat has a piston and cylinder type temperature responsive device operatively associated with said main valve member for moving said main valve member relative to said main valve seat.

Claim 4

A system as set forth in claim 2 wherein said device has a cylinder member, said main valve member being secured to cylinder member to said move in unison therewith, said flexible vent valve member being carried by said cylinder member adjacent said valve member.

Claim 5

In an internal combustion engine coolant system having a radiator for receiving coolant into an inlet thereof from an outlet of said engine through a thermostat disposed intermediate said outlet of said engine and said inlet of said radiator and having a coolant pump for circulating said coolant through said engine from an inlet of said engine to said outlet thereof, said pump having a first inlet interconnected to said outlet of said engine upstream of said thermostat and a second inlet interconnected to the outlet of said radiator while having its outlet interconnected to said inlet of said engine, said thermostat having a vent valve means carried by the main valve member thereof for venting air from said outlet of said engine to said inlet of said radiator when said main valve member of said thermostat is in a closed condition against the main valve seal thereof and said system is being filled with coolant that is being introduced into said radiator and for preventing coolant flow through said vent valve means when said pump is circulating said coolant and said main valve member of said thermostat is in a closed condition against said main valve seat, the improvement wherein said vent valve means comprises a vent opening through said main valve member and a flexible vent valve member for opening and closing said vent opening, said main valve member having a substantially flat surface surrounding said vent opening, said flat surface having abutment means extending outwardly from said flat surface adjacent said vent opening, said flexible vent valve member being adapted to engage said abutment means in one flexed condition thereof to seal around said vent opening at said surface to close said vent opening and to engage said abutment means in another flexed condition thereof that will not seal around said vent opening at said surface so that said vent opening is open.

Claim 6

In an internal combustion engine coolant system having a radiator for receiving coolant into an inlet thereof from an outlet of said engine through a thermostat disposed intermediate said outlet of said engine and said inlet of said radiator and having a coolant pump for circulating said coolant through said engine from an inlet of said engine to said outlet thereof, said pump having a first inlet interconnected to said outlet of said engine upstream of said thermostat and a second inlet interconnected to the outlet of said radiator while having its outlet interconnected to said inlet of said engine, said thermostat having a vent valve means carried by the main valve member thereof for venting air from said outlet of said engine to said inlet of said radiator when said main valve member of said thermostat is in a closed condition against the main valve seal thereof and said system is being filled with coolant that is being introduced into said radiator and for preventing coolant flow through said vent valve means when said pump is circulating said coolant and said main valve member of said thermostat is in a closed condition against said main valve seat, the improvement wherein said vent valve means comprises a vent opening through said main valve member and a flexible vent valve member for opening and closing said vent opening, said main valve member having a substantially flat surface surrounding said vent opening, said flat surface having abutment means extending outwardly from said flat surface adjacent said vent opening, said flexible vent valve member being adapted to engage said abutment means in one flexed condition thereof to seal around said vent opening at said surface to close said vent opening and to engage said abutment means in another flexed condition thereof that will not seal around said vent opening at said surface so that said vent opening is open.

Claim 7

A system as set forth in claim 4 wherein said abutment means comprise a plurality of abutments.

Claim 8

A system as set forth in claim 5 wherein said plurality of abutments comprises two abutments disposed on opposite sides of said vent opening.

Claim 9

A system as set forth in claim 6 wherein said flexible valve member spans said abutments.

Claim 10

In an internal combustion engine coolant system having a radiator for receiving coolant into an inlet thereof from an outlet of said engine through a thermostat disposed intermediate said outlet of said engine and said inlet of said radiator and having a coolant pump for circulating said coolant through said engine from an inlet of said engine to said outlet thereof, said pump having a first inlet interconnected to said outlet of said engine upstream of said thermostat and a second inlet interconnected to the outlet of said radiator while having its outlet interconnected to said inlet of said engine, said thermostat having a vent valve means carried by the main valve member thereof for venting air from said outlet of said engine to said inlet of said radiator when said main valve member of said thermostat is in a closed condition against the main valve seat thereof and said system is being filled with coolant that is being introduced into said radiator and for preventing coolant flow through said vent valve means when said pump is circulating said coolant and said main valve member of said thermostat is in a closed condition against said main valve seat, the improvement wherein said vent valve means comprises a vent opening through said main valve member and a flexible vent valve member for opening and closing said vent opening, said thermostat having a piston and cylinder type temperature responsive device operatively associated with said main valve member for moving said main valve member relative to said main valve seat, said device having a cylinder member, said main valve member being secured to said cylinder member to move in unison therewith, said flexible vent valve member being carried by said cylinder member adjacent said valve member, said cylinder member having an annular shoulder spaced from said main valve member, said flexible vent valve member comprising a washer like member having an inner peripheral portion disposed against said shoulder and an outer peripheral portion extending outboard of said vent opening.

Claim 11

In an internal combustion engine coolant system having a radiator for receiving coolant into an inlet thereof from an outlet of said engine through a thermostat disposed intermediate said outlet of said engine and said inlet of said radiator and having a coolant pump for circulating said coolant through said engine from an inlet of said engine to said outlet thereof, said pump having a first inlet interconnected to said outlet of said engine upstream of said thermostat and a second inlet interconnected to the outlet of said radiator while having its outlet interconnected to said inlet of said engine, said thermostat having a vent valve means carried by the main valve member thereof for venting air from said outlet of said engine to said inlet of said radiator when said main valve member of said thermostat is in a closed condition against the main valve seat thereof and said system is being filled with coolant that is being introduced into said radiator and for preventing coolant flow through said vent valve means when said pump is circulating said coolant and said main valve member of said thermostat is in a closed condition against said main valve seat, the improvement wherein said vent valve means comprises a vent opening through said main valve member and a flexible vent valve member for opening and closing said vent opening, said thermostat having a piston and cylinder type temperature responsive device operatively associated with said main valve member for moving said main valve member relative to said main valve seat, said device having a cylinder member, said main valve member being secured to said cylinder member to move in unison therewith, said flexible vent valve member being carried by said cylinder member adjacent said valve member, said cylinder member having an annular shoulder spaced from said main valve member, said flexible vent valve member comprising a washer like member having an inner peripheral portion disposed against said shoulder and an outer peripheral portion extending outboard of said vent opening.

Claim 12

A system as set forth in claim 8 wherein said main valve member has a substantially flat surface surrounding said vent opening, said flat surface having two abutment means extending outwardly from said flat surface adjacent said vent opening and on opposite sides thereof, said flexible vent valve member being adapted to engage said abutment means in one flexed condition thereof to seal around said vent opening at said surface and intermediate said inner and outer peripheral portions thereof to close said vent opening and to engage said abutment means in another flexed condition thereof that will not seal around said vent opening at said surface so that said vent opening is open to beyond said outer peripheral portion of said flexible vent valve member intermediate said surface and said flexible vent valve member and intermediate said abutment means.

Claim 13

A system as set forth in claim 9 wherein said thermostat has a coiled compression spring provided with one end bearing against said main valve member to tend to move said main valve member toward said main valve seat, said outer peripheral portion of said flexible vent valve member being disposed concentrically within said one end of said coiled compression spring and inboard thereof.

Claim 14

In a method of making an internal combustion engine coolant system having a radiator for receiving coolant into an inlet thereof from an outlet of said engine through a thermostat disposed intermediate said outlet of said engine and said inlet of said radiator and having a coolant pump for circulating said coolant through said engine from an inlet of said engine to said outlet thereof, said pump having a first inlet interconnected to said outlet of said engine upstream of said thermostat and a second inlet interconnected to the outlet of said radiator while having its outlet interconnected to said inlet of said engine, said thermostat having a vent valve means carried by the main valve member thereof for venting air from said outlet of said engine to said inlet of said radiator when said main valve member of said thermostat is in a closed condition against the main valve seat thereof and said system is being filled with coolant that is being introduced into said radiator and for preventing coolant flow through said vent valve means when said pump is circulating said coolant and said main valve member of said thermostat is in a closed condition against said main valve seat, the improvement comprising the steps of forming said vent valve means to comprise a vent opening through said main valve member and a flexible vent valve member for opening and closing said vent opening, and forming said flexible vent valve member to be normally held in spaced relation from said vent opening and to be adapted to be flexed against said vent opening to close said vent opening by said coolant being circulated by said pump.

Claim 15

In a method of making an internal combustion engine coolant system having a radiator for receiving coolant into an inlet thereof from an outlet of said engine through a thermostat disposed intermediate said outlet of said engine and said inlet of said radiator and having a coolant pump for circulating said coolant through said engine from an inlet of said engine to said outlet thereof, said pump having a first inlet interconnected to said outlet of said engine upstream of said thermostat and a second inlet interconnected to the outlet of said radiator while having its outlet interconnected to said inlet of said engine, said thermostat having a vent valve means carried by the main valve member thereof for venting air from said outlet of said engine to said inlet of said radiator when said main valve member of said thermostat is in a closed condition against the main valve seat thereof and said system is being filled with coolant that is being introduced into said radiator and for preventing coolant flow through said vent valve means when said pump is circulating said coolant and said main valve member of said thermostat is in a closed condition against said main valve seat, the improvement comprising the steps of forming said vent valve means to comprise a vent opening through said main valve member and a flexible vent valve member for opening and closing said vent opening, and forming said flexible vent valve member to be normally held in spaced relation from said vent opening and to be adapted to be flexed against said vent opening to close said vent opening by said coolant being circulated by said pump.

Claim 16

A method of making a system as set forth in claim 11 and including the steps of forming said thermostat with a piston and cylinder type temperature responsive device, and operatively associating said device with said main valve member for moving said main valve member relative to said main valve seat.

Claim 17

A method of making a system as set forth in claim 12 and including the steps of forming said device to have a cylinder member, securing said main valve member to said cylinder member to move in unison therewith, and disposing said flexible vent valve member to be carried by said cylinder member adjacent said valve member.

Claim 18

In a method of making an internal combustion engine coolant system having a radiator for receiving coolant into an inlet thereof from an outlet of said engine through a thermostat disposed intermediate said outlet of said engine and said inlet of said radiator and having a coolant pump for circulating said coolant through said engine from an inlet of said engine to said outlet thereof, said pump having a first inlet interconnected to said outlet of said engine upstream of said thermostat and a second inlet interconnected to the outlet of said radiator while having its outlet interconnected to said inlet of said engine, said thermostat having a vent valve means carried by the main valve member thereof for venting air from said outlet of said engine to said inlet of said radiator when said main valve member of said thermostat is in a closed condition against the main valve seat thereof and said system is being filled with coolant that is being introduced into said radiator and for preventing coolant flow through said vent valve means when said pump is circulating said coolant and said main valve member of said thermostat is in a closed condition against said main valve seat, the improvement comprising the steps of forming said vent valve means to comprise a vent opening through said main valve member and a flexible vent valve member for opening and closing said vent opening, forming said main valve member to have a substantially flat surface surrounding said vent opening, forming said flat surface to have abutment means extending outwardly from said flat surface adjacent said vent opening, and disposing said flexible vent valve member to be adapted to engage said abutment means in one flexed condition thereof to seal around said vent opening at said surface to close said vent opening and to engage said abutment means in another flexed condition thereof that will not seal around said vent opening at said surface so that said vent opening is open.

Claim 19

In a method of making an internal combustion engine coolant system having a radiator for receiving coolant into an inlet thereof from an outlet of said engine through a thermostat disposed intermediate said outlet of said engine and said inlet of said radiator and having a coolant pump for circulating said coolant through said engine from an inlet of said engine to said outlet thereof, said pump having a first inlet interconnected to said outlet of said engine upstream of said thermostat and a second inlet interconnected to the outlet of said radiator while having its outlet interconnected to said inlet of said engine, said thermostat having a vent valve means carried by the main valve member thereof for venting air from said outlet of said engine to said inlet of said radiator when said main valve member of said thermostat is in a closed condition against the main valve seat thereof and said system is being filled with coolant that is being introduced into said radiator and for preventing coolant flow through said vent valve means when said pump is circulating said coolant and said main valve member of said thermostat is in a closed condition against said main valve seat, the improvement comprising the steps of forming said vent valve means to comprise a vent opening through said main valve member and a flexible vent valve member for opening and closing said vent opening, forming said main valve member to have a substantially flat surface surrounding said vent opening, forming said flat surface to have abutment means extending outwardly from said flat surface adjacent said vent opening, and disposing said flexible vent valve member to be adapted to engage said abutment means in one flexed condition thereof to seal around said vent opening at said surface to close said vent opening and to engage said abutment means in another flexed condition thereof that will not seal around said vent opening at said surface so that said vent opening is open.

Claim 20

A method of making a system as set forth in claim 14 and including the step of forming said abutment means to comprise a plurality of abutments.

Claim 21

A method of making a system as set forth in claim 15 and including the step of forming said plurality of abutments to comprise two abutments disposed on opposite sides of said vent opening.

Claim 22

A method of making a system as set forth in claim 16 and including the step of disposing said flexible valve member to span said two abutments.

Claim 23

In a method of making an internal combustion engine coolant system having a radiator for receiving coolant into an inlet thereof from an outlet of said engine through a thermostat disposed intermediate said outlet of said engine and said inlet of said radiator and having a coolant pump for circulating said coolant through said engine from an inlet of said engine to said outlet thereof, said pump having a first inlet interconnected to said outlet of said engine upstream of said thermostat and a second inlet interconnected to the outlet of said radiator while having its outlet interconnected to said inlet of said engine, said thermostat having a vent valve means carried by the main valve member thereof for venting air from said outlet of said engine to said inlet of said radiator when said main valve member of said thermostat is in a closed condition against the main valve seat thereof and said system is being filled with coolant that is being introduced into said radiator and for preventing coolant flow through said vent valve means when said pump is circulating said coolant and said main valve member of said thermostat is in a closed condition against said main valve seat, the improvement comprising the steps of forming said vent valve means to comprise a vent opening through said main valve member and a flexible vent valve member for opening and closing said vent opening, forming said thermostat with a piston and cylinder type temperature responsive device, operatively associating said device with said main valve member for moving said main valve member relative to said main valve seat, forming said device to have a cylinder member, securing said main valve member to said cylinder member to move in unison therewith, disposing said flexible vent valve member to be carried by said cylinder member adjacent said valve member, forming said cylinder member to have an annular shoulder spaced from said main valve member, forming said flexible vent valve member to comprise a washer like member, and disposing an inner peripheral portion of said washer like member against said shoulder with an outer peripheral portion thereof extending outboard of said vent opening.

Claim 24

In a method of making an internal combustion engine coolant system having a radiator for receiving coolant into an inlet thereof from an outlet of said engine through a thermostat disposed intermediate said outlet of said engine and said inlet of said radiator and having a coolant pump for circulating said coolant through said engine from an inlet of said engine to said outlet thereof, said pump having a first inlet interconnected to said outlet of said engine upstream of said thermostat and a second inlet interconnected to the outlet of said radiator while having its outlet interconnected to said inlet of said engine, said thermostat having a vent valve means carried by the main valve member thereof for venting air from said outlet of said engine to said inlet of said radiator when said main valve member of said thermostat is in a closed condition against the main valve seat thereof and said system is being filled with coolant that is being introduced into said radiator and for preventing coolant flow through said vent valve means when said pump is circulating said coolant and said main valve member of said thermostat is in a closed condition against said main valve seat, the improvement comprising the steps of forming said vent valve means to comprise a vent opening through said main valve member and a flexible vent valve member for opening and closing said vent opening, forming said thermostat with a piston and cylinder type temperature responsive device, operatively associating said device with said main valve member for moving said main valve member relative to said main valve seat, forming said device to have a cylinder member, securing said main valve member to said cylinder member to move in unison therewith, disposing said flexible vent valve member to be carried by said cylinder member adjacent said valve member, forming said cylinder member to have an annular shoulder spaced from said main valve member, forming said flexible vent valve member to comprise a washer like member, and disposing an inner peripheral portion of said washer like member against said shoulder with an outer peripheral portion thereof extending outboard of said vent opening.

Claim 25

A method of making a system as set forth in claim 18 and including the steps of forming said main valve member to have a substantially flat surface surrounding said vent opening, forming said flat surface to have two abutment means extending outwardly from said flat surface adjacent said vent opening and on opposite sides thereof, and disposing said flexible vent valve member to be adapted to engage said abutment means in one flexed condition thereof to seal around said vent opening at said surface and intermediate said inner and outer peripheral portions thereof to close said vent opening and to engage said abutment means in another flexed condition thereof that will not seal around said vent opening at said surface so that said vent opening is open to beyond said outer peripheral portion of said flexible vent valve member intermediate said surface and said flexible vent valve member and intermediate said abutment means.

Claim 26

A method of making a system as set forth in claim 19 and including the steps of forming said thermostat with a coiled compression spring, bearing one end of said spring against said main valve member to tend to move said main valve member toward said main valve seat, and disposing said outer peripheral portion of said flexible vent valve member concentrically within said one end of said coiled compression spring and inboard thereof.

Claim 27

In a thermostat for an internal com-engine coolant system having a radiator for receiving coolant into an inlet thereof from an outlet of said engine through said thermostat when disposed intermediate said outlet of said engine and said inlet of said radiator and having a coolant pump for circulating said coolant through said engine from an inlet of said engine to said outlet thereof, said thermostat having a vent valve means carried by the main valve member thereof for venting air from said outlet of said engine to said inlet of said radiator when said main valve member of said thermostat is in a closed condition against the main valve seat thereof and said system is being filled with coolant that is being introduced into said radiator and for preventing coolant flow through said vent valve means when said pump is circulating said coolant and said main valve member of said thermostat is in a closed condition against said main valve seat, the improvement wherein said vent valve means comprises a vent opening through said main valve member and a flexible vent valve member for opening and closing said vent opening, said flexible vent valve member normally being held in spaced relation from said vent opening and being adapted to be flexed against said vent opening to close said vent opening by said coolant being circulated by said pump.

Claim 28

In a thermostat for an internal com-engine coolant system having a radiator for receiving coolant into an inlet thereof from an outlet of said engine through said thermostat when disposed intermediate said outlet of said engine and said inlet of said radiator and having a coolant pump for circulating said coolant through said engine from an inlet of said engine to said outlet thereof, said thermostat having a vent valve means carried by the main valve member thereof for venting air from said outlet of said engine to said inlet of said radiator when said main valve member of said thermostat is in a closed condition against the main valve seat thereof and said system is being filled with coolant that is being introduced into said radiator and for preventing coolant flow through said vent valve means when said pump is circulating said coolant and said main valve member of said thermostat is in a closed condition against said main valve seat, the improvement wherein said vent valve means comprises a vent opening through said main valve member and a flexible vent valve member for opening and closing said vent opening, said flexible vent valve member normally being held in spaced relation from said vent opening and being adapted to be flexed against said vent opening to close said vent opening by said coolant being circulated by said pump.

Claim 29

A thermostat as set forth in claim 21 wherein said thermostat has a piston and cylinder type temperature responsive device operatively associated with said main valve member for moving said main valve member relative to said main valve seat.

Claim 30

A thermostat as set forth in claim 22 wherein said device has a cylinder member, said main valve member being secured to said cylinder member to move in unison therewith, said flexible vent valve member being carried by said cylinder member adjacent said valve member.

Claim 31

In a thermostat for an internal combustion engine coolant system having a radiator for receiving coolant into an inlet thereof from an outlet of said engine through said thermostat when disposed intermediate said outlet of said engine and said inlet of said radiator and having a coolant pump for circulating said coolant through said engine from an inlet of said engine to said outlet thereof, said thermostat having a vent valve means carried by the main valve member thereof for venging air from said outlet of said engine to said inlet of said radiator when said main valve member of said thermostat is in a closed condition against the main valve seat thereof and said system is being filled with coolant that is being introduced into said radiator and for preventing coolant flow through said vent valve means when said pump is circulating said coolant and said main valve member of said thermostat is in a closed condition against said main valve seat, the improvement wherein said vent valve means comprises a vent opening through said main valve member and a flexible vent valve member for opening and closing said vent opening, said main valve member having a substantially flat surface surrounding said vent opening, said flat surface having abutment means extending outwardly from said flat surface adjacent said vent opening, said flexible vent valve member being adapted to engage said abutment means in one flexed condition thereof to seal around said vent opening at said surface to close said vent opening and to engage said abutment means in another flexed condition thereof that will not seal around said vent opening at said surface so that said vent opening is open.

Claim 32

In a thermostat for an internal combustion engine coolant system having a radiator for receiving coolant into an inlet thereof from an outlet of said engine through said thermostat when disposed intermediate said outlet of said engine and said inlet of said radiator and having a coolant pump for circulating said coolant through said engine from an inlet of said engine to said outlet thereof, said thermostat having a vent valve means carried by the main valve member thereof for venging air from said outlet of said engine to said inlet of said radiator when said main valve member of said thermostat is in a closed condition against the main valve seat thereof and said system is being filled with coolant that is being introduced into said radiator and for preventing coolant flow through said vent valve means when said pump is circulating said coolant and said main valve member of said thermostat is in a closed condition against said main valve seat, the improvement wherein said vent valve means comprises a vent opening through said main valve member and a flexible vent valve member for opening and closing said vent opening, said main valve member having a substantially flat surface surrounding said vent opening, said flat surface having abutment means extending outwardly from said flat surface adjacent said vent opening, said flexible vent valve member being adapted to engage said abutment means in one flexed condition thereof to seal around said vent opening at said surface to close said vent opening and to engage said abutment means in another flexed condition thereof that will not seal around said vent opening at said surface so that said vent opening is open.

Claim 33

A thermostat as set forth in claim 24 wherein said abutment means comprise a plurality of abutments.

Claim 34

A thermostat as set forth in claim 25 wherein said plurality of abutments comprises two abutments disposed on opposite sides of said vent opening.

Claim 35

A thermostat as set forth in claim 26 wherein said flexible valve member spans said two abutments.

Claim 36

In a thermostat for an internal combustion engine coolant system having a radiator for receiving coolant into an inlet thereof from an outlet of said engine through said thermostat when disposed intermediate said outlet of said engine and said inlet of said radiator and having a coolant pump for circulating said coolant through said engine from an inlet of said engine to said outlet thereof, said thermostat having a vent valve means carried by the main valve member thereof for venting air from said outlet of said engine to said inlet of said radiator when said main valve member of said thermostat is in a closed condition against the main valve seat thereof and said system is being filled with coolant that is being introduced into said radiator and for preventing coolant flow through said vent valve means when said pump is circulating said coolant and said main valve member of said thermostat is in a closed condition against said main valve seat, the improvement wherein said vent valve means comprises a vent opening through said main valve member and a flexible vent valve member for opening and closing said vent opening, said thermostat having a piston and cylinder type temperature responsive device operatively associated with said main valve member for moving said main valve member relative to said main valve seat, said device having a cylinder member, said main valve member being secured to said cylinder member to move in unison therewith, said flexible vent valve member being carried by said cylinder member adjacent said valve member, said cylinder member having an annular shoulder spaced from said main valve member, said flexible vent valve member comprising a washer like member having an inner peripheral portion disposed against said shoulder and an outer peripheral portion extending outboard of said vent opening.

Claim 37

In a thermostat for an internal combustion engine coolant system having a radiator for receiving coolant into an inlet thereof from an outlet of said engine through said thermostat when disposed intermediate said outlet of said engine and said inlet of said radiator and having a coolant pump for circulating said coolant through said engine from an inlet of said engine to said outlet thereof, said thermostat having a vent valve means carried by the main valve member thereof for venting air from said outlet of said engine to said inlet of said radiator when said main valve member of said thermostat is in a closed condition against the main valve seat thereof and said system is being filled with coolant that is being introduced into said radiator and for preventing coolant flow through said vent valve means when said pump is circulating said coolant and said main valve member of said thermostat is in a closed condition against said main valve seat, the improvement wherein said vent valve means comprises a vent opening through said main valve member and a flexible vent valve member for opening and closing said vent opening, said thermostat having a piston and cylinder type temperature responsive device operatively associated with said main valve member for moving said main valve member relative to said main valve seat, said device having a cylinder member, said main valve member being secured to said cylinder member to move in unison therewith, said flexible vent valve member being carried by said cylinder member adjacent said valve member, said cylinder member having an annular shoulder spaced from said main valve member, said flexible vent valve member comprising a washer like member having an inner peripheral portion disposed against said shoulder and an outer peripheral portion extending outboard of said vent opening.

Claim 38

A thermostat as set forth in claim 28 wherein said main valve member has a substantially flat surface surrounding said vent opening, said flat surface having two abutment means extending outwardly from said flat surface adjacent said vent opening and an opposite sides thereof, said flexible vent valve member being adapted to engage said abutment means in one flexed condition thereof to seal around said vent opening at said surface and intermediate said inner and outer peripheral portions thereof to close said vent opening and to engage said abutment means in another flexed condition thereof that will not seal around said vent opening at said surface so that said vent opening is open to beyond said outer peripheral portion of said flexible vent valve member intermediate said surface and said flexible vent valve member and intermediate said abutment means.

Claim 39

A thermostat as set forth in claim 29 wherein said thermostat has a coiled compression spring provided with one end bearing against said main valve member to tend to move said main valve member toward said main valve seat, said outer peripheral portion of said flexible vent valve member being disposed concentrically within said one end of said coiled compression spring and inboard thereof.

Claim 40

In a method of making a thermostat for an internal combustion engine coolant system having a radiator for receiving coolant into an inlet thereof from an outlet of said engine through said thermostat when disposed intermediate said outlet of said engine and said inlet of said radiator and having a coolant pump for circulating said coolant through said engine from an inlet of said engine to said outlet thereof, said thermostat having a vent valve means carried by the main valve member thereof for venting air from said outlet of said engine to said inlet of said radiator when said main valve member of said thermostat is in a closed condition against the main valve seat thereof and said system is being filled with coolant that is being introduced into said radiator and for preventing coolant flow through said vent valve means when said pump is circulating said coolant and said main valve member of said thermostat is in a closed condition against said main valve seat, the improvement comprising the steps of forming said vent valve means to comprise a vent opening through said main valve member and a flexible vent valve member for opening and closing said vent opening, and forming said flexible vent valve member to be normally held in spaced relation from said vent opening and to be adapted to be flexed against said vent opening to close said vent opening by said coolant being circulated by said pump.

Claim 41

In a method of making a thermostat for an internal combustion engine coolant system having a radiator for receiving coolant into an inlet thereof from an outlet of said engine through said thermostat when disposed intermediate said outlet of said engine and said inlet of said radiator and having a coolant pump for circulating said coolant through said engine from an inlet of said engine to said outlet thereof, said thermostat having a vent valve means carried by the main valve member thereof for venting air from said outlet of said engine to said inlet of said radiator when said main valve member of said thermostat is in a closed condition against the main valve seat thereof and said system is being filled with coolant that is being introduced into said radiator and for preventing coolant flow through said vent valve means when said pump is circulating said coolant and said main valve member of said thermostat is in a closed condition against said main valve seat, the improvement comprising the steps of forming said vent valve means to comprise a vent opening through said main valve member and a flexible vent valve member for opening and closing said vent opening, and forming said flexible vent valve member to be normally held in spaced relation from said vent opening and to be adapted to be flexed against said vent opening to close said vent opening by said coolant being circulated by said pump.

Claim 42

A method of making a thermostat as set forth in claim 31 and including the steps of forming said thermostat with a piston and cylinder type temperature responsive device, and operatively associating said device with said main valve member for moving said main valve member relative to said main valve seat.

Claim 43

A method of making a thermostat as set forth in claim 32 and including the steps of forming said device to have a cylinder member, securing said main valve member to said cylinder member to move in unison therewith, and disposing said flexible vent valve member to be carried by said cylinder member adjacent said valve member.

Claim 44

In a method of making a thermostat for an internal combustion engine coolant system having a radiator for receiving coolant into an inlet thereof from an outlet of said engine through said thermostat when disposed intermediate said outlet of said engine and said inlet of said radiator and having a coolant pump for circulating said coolant through said engine from an inlet of said engine to said outlet thereof, said thermostat having a vent valve means carried by the main valve member thereof for venting air from said outlet of said engine to said inlet of said radiator when said main valve member of said thermostat is in a closed condition against the main valve seat thereof and said system is being filled with coolant that is being introduced into said radiator and for preventing coolant flow through said vent valve means when said pump is circulating said coolant and said main valve member of said thermostat is in a closed condition against said main valve seat, the improvement comprising the steps of forming said vent valve means to comprise a vent opening through said main valve member and a flexible vent valve member for opening and closing said vent opening, forming said main valve member to have a substantially flat surface surrounding said vent opening, forming said flat surface to have abutment means extending outwardly from said flat surface adjacent said vent opening, and disposing said flexible vent valve member to be adapted to engage said abutment means in one flexed condition thereof to seal around said vent opening at said surface to close said vent opening and to engage said abutment means in another flexed condition thereof that will not seal around said vent opening at said surface so that said vent opening is open.

Claim 45

In a method of making a thermostat for an internal combustion engine coolant system having a radiator for receiving coolant into an inlet thereof from an outlet of said engine through said thermostat when disposed intermediate said outlet of said engine and said inlet of said radiator and having a coolant pump for circulating said coolant through said engine from an inlet of said engine to said outlet thereof, said thermostat having a vent valve means carried by the main valve member thereof for venting air from said outlet of said engine to said inlet of said radiator when said main valve member of said thermostat is in a closed condition against the main valve seat thereof and said system is being filled with coolant that is being introduced into said radiator and for preventing coolant flow through said vent valve means when said pump is circulating said coolant and said main valve member of said thermostat is in a closed condition against said main valve seat, the improvement comprising the steps of forming said vent valve means to comprise a vent opening through said main valve member and a flexible vent valve member for opening and closing said vent opening, forming said main valve member to have a substantially flat surface surrounding said vent opening, forming said flat surface to have abutment means extending outwardly from said flat surface adjacent said vent opening, and disposing said flexible vent valve member to be adapted to engage said abutment means in one flexed condition thereof to seal around said vent opening at said surface to close said vent opening and to engage said abutment means in another flexed condition thereof that will not seal around said vent opening at said surface so that said vent opening is open.

Claim 46

A method of making a thermostat as set forth in claim 34 and including the step of forming said abutment means to comprise a plurality of abutments.

Claim 47

A method of making a thermostat as set forth in claim 35 and including the step of forming said plurality of abutments to comprise two abutments disposed on opposite sides of said vent opening.

Claim 48

A method of making a thermostat as set forth in claim 36 and including the step of disposing said flexible valve member to span said two abutments.

Claim 49

In a method of making a thermostat for an internal combustion engine coolant system having a radiator for receiving coolant into an inlet thereof from an outlet of said engine through said thermostat when disposed intermediate said outlet of said engine and said inlet of said radiator and having a coolant pump for circulating said coolant through said engine from an inlet of said engine to said outlet thereof, said thermostat having a vent valve means carried by the main valve member thereof for venting air from said outlet of said engine to said inlet of said radiator when said main valve member of said thermostat is in a closed condition against the main valve seat thereof and said system is being filled with coolant that is being introduced into said radiator and for preventing coolant flow through said vent valve means when said pump is circulating said coolant and said main valve member of said thermostat is in a closed condition against said main valve seat, the improvement comprising the steps of forming said vent valve means to comprise a vent opening through said main valve member and a flexible vent valve member for opening and closing said vent opening, forming said thermostat with a piston and cylinder type temperature responsive device, operatively associating said device with said main valve member for moving said main valve member relative to said main valve seat, forming said device to have a cylinder member, securing said main valve member to said cylinder member to move in unison therewith, disposing said flexible vent valve member to be carried by said cylinder member adjacent said valve member, forming said cylinder member to have an annular shoulder spaced from said main valve member, forming said flexible vent valve member to comprise a washer like member, and disposing an inner peripheral portion of said washer like member against said shoulder with an outer peripheral portion thereof extending outboard of said vent opening.

Claim 50

In a method of making a thermostat for an internal combustion engine coolant system having a radiator for receiving coolant into an inlet thereof from an outlet of said engine through said thermostat when disposed intermediate said outlet of said engine and said inlet of said radiator and having a coolant pump for circulating said coolant through said engine from an inlet of said engine to said outlet thereof, said thermostat having a vent valve means carried by the main valve member thereof for venting air from said outlet of said engine to said inlet of said radiator when said main valve member of said thermostat is in a closed condition against the main valve seat thereof and said system is being filled with coolant that is being introduced into said radiator and for preventing coolant flow through said vent valve means when said pump is circulating said coolant and said main valve member of said thermostat is in a closed condition against said main valve seat, the improvement comprising the steps of forming said vent valve means to comprise a vent opening through said main valve member and a flexible vent valve member for opening and closing said vent opening, forming said thermostat with a piston and cylinder type temperature responsive device, operatively associating said device with said main valve member for moving said main valve member relative to said main valve seat, forming said device to have a cylinder member, securing said main valve member to said cylinder member to move in unison therewith, disposing said flexible vent valve member to be carried by said cylinder member adjacent said valve member, forming said cylinder member to have an annular shoulder spaced from said main valve member, forming said flexible vent valve member to comprise a washer like member, and disposing an inner peripheral portion of said washer like member against said shoulder with an outer peripheral portion thereof extending outboard of said vent opening.

Claim 51

A method of making a thermostat as set forth in claim 38 and including the steps of forming said main valve member to have a substantially flat surface surrounding said vent opening, forming said flat surface to have two abutment means extending outwardly from said flat surface adjacent said vent opening and on opposite sides thereof, and disposing said flexible vent valve member to be adapted to engage said abutment means in one flexed condition thereof to seal around said vent opening at said surface and intermediate said inner and outer peripheral portions thereof to close said vent opening and to engage said abutment means in another flexed condition thereof that will not seal around said vent opening at said surface so that said vent opening is open to beyond said outer peripheral portion of said flexible vent valve member intermediate said surface and said flexible vent valve member and intermediate said abutment means.

Claim 52

A method of making a thermostat as set forth in claim 39 and including the steps of forming said thermostat with a coiled compression spring, bearing one end of said spring against said main valve member to tend to move said main valve member toward said main valve seat, and disposing said outer peripheral portion of said flexible vent valve member concentrically within said one end of said coiled compression spring and inboard thereof.