Temperature compensated fill valve/pressure switch

Claim 2

An improved fluid pressure monitoring switch of the type including a housing adapted for mounting within a container, at least one moving contact and at least one fixed contact both disposed within said housing, said switch operative to monitor the fluid pressure within the container and to shift from a first contact state to a second contact state when the fluid pressure falls below a selected level, the improvement comprising; a capsule comprising a substantially rigid wall member and a compliant wall member, said wall members defining therebetween a sealed cavity pressurized to a predetermined value, means whereby said compliant wall member is operative to virtually effect a preselectable compensation characteristic by substantially varying the volume of said cavity as a function of cavity and container fluid pressures, said compliant wall member operatively engaging said moving contact for displacement with respect to said fixed contact as a function of fluid temperature within said capsule, and thereby varying said selected level as a function of said fluid temperature; and capsule retention means operative to maintain said rigid wall member in a fixed relationship with said housing.

Claim 3

The device of claim 1, wherein said compliant wall member comprises a metal diaphragm.

Claim 4

The device of claim 1, wherein in said first contact state, said contacts are electrically open, and in said second contact state, said contacts are electrically closed.

Claim 5

The device of claim 3, wherein said housing is constructed of electrically conducting material and is connected to said moving contact.

Claim 6

The device of claim 1, further comprising plunger means disposed between said compliant wall member and said moving contact, and is displaceable therewith.

Claim 7

The device of claim 1 wherein said capsule retention means is defined by a portion of said housing which nestingly engages said rigid wall member.

Claim 8

The device of claim 1, wherein said capsule retention means further comprises manual calibration means operative to vary said selected level.

Claim 9

The device of claim 1, wherein said predetermined value equals said selected level.

Claim 12

The device of claim 9, wherein said second wall member comprises a metal diaphragm.

Claim 13

The device of claim 9, wherein in said first contact state, said switch means is electrically open, and in said second contact state, said switch means is electrically closed.

Claim 14

The device of claim 11, wherein said body portion is constructed of electrically conducting material and is connected to said fixed contact.

Claim 15

The device of claim 9, further comprising plunger means disposed between said second wall member and said moving contact, and is displaceable therewith.

Claim 16

The device of claim 9, wherein said capsule retention means comprises cooperating threads formed in said body portion and first wall member.

Claim 17

The device of claim 14, wherein said threads are aligned substantially coaxially with said inlet passage.

Claim 18

The device of claim 9, wherein said capsule retention means further comprises manual calibration means operative to vary said selected level.

Claim 19

The device of claim 9, wherein said predetermined value equals said selected level.

Claim 22

The method of claim 18, further comprising the step of calibrating said device by selectively repositioning said capsule with respect to said body under known temperature and pressure conditions.

Claim 23

The method of claim 18, wherein the step of forming said capsule comprises the sub-steps of: forming said first wall member to define a capsule pressurizing aperture; forming said second wall member; and sealingly engaging said first and second wall members to define said cavity.

Claim 24

The method of claim 20, wherein the step of sealing said cavity comprises plugging said capsule pressurizing aperture after the fluid within said cavity has been pressurized.

Claim 25

The method of claim 18, wherein said capsule is installed within said body after said switch means.

Claim 26

The method of claim 18, wherein said capsule is installed within said body before said switch means.

Claim 27

The method of claim 18, wherein said step of pressurizing fluid within said cavity comprises pressurizing said fluid to a predetermined value which equals said selected level.

Claim 28

A fill valve/temperature compensated pressure switch adapted for use with a pneumatic tire and associated mating wheel, said valve-switch comprising: a body defining a switch receiving portion and a valve stem portion, said switch receiving portion adapted to be positioned adjacent the inside surface of a wall of said wheel with said valve stem portion for projecting outwardly through an aperture in said wall, said valve stem portion defining valve core receiving means within an inlet passage for interconnecting the interior of said tire with the atmosphere; a valve core disposed within said inlet passage and operative to selectively pass air therethrough; a switch disposed within said switch receiving portion and comprising at least one moving electrical contact and at least one fixed electrical contact, the switch operating to monitor the air pressure within the tire and to change conductive state when the air pressure falls below a set point level; a prepressurized temperature compensating sealed capsule comprising a rigid body portion and a compliant diaphragm disposed within the switch receiving portion and means whereby said diaphragm is operatively engaging the switch to displace the moving contact with respect to the fixed contact as a function of fluid temperature within the capsule and thereby vary the set point level as a function of the air temperature within the tire, said diaphragm operable, under the influence of cavity and tire fluid pressures, for inward and outward excursions with respect to said rigid body portion while in a first contact state, to substantially vary the volume of said cavity as a function of said cavity and tire fluid pressures to virtually effect a preselectable temperature compensation characteristic; and means operative to selectively position the rigid body portion of the capsule with respect to the switch to effect establishment of said set point level

Claim 29

A fill valve/temperature compensated pressure switch adapted for use with a pneumatic tire and associated mating wheel, said valve-switch comprising: a body defining a switch receiving portion and a valve stem portion, said switch receiving portion adapted to be positioned adjacent the inside surface of a wall of said wheel with said valve stem portion for projecting outwardly through an aperture in said wall, said valve stem portion defining valve core receiving means within an inlet passage for interconnecting the interior of said tire with the atmosphere; a valve core disposed within said inlet passage and operative to selectively pass air therethrough; a switch disposed within said switch receiving portion and comprising at least one moving electrical contact and at least one fixed electrical contact, the switch operating to monitor the air pressure within the tire and to change conductive state when the air pressure falls below a set point level; a prepressurized temperature compensating sealed capsule comprising a rigid body portion and a compliant diaphragm disposed within the switch receiving portion and means whereby said diaphragm is operatively engaging the switch to displace the moving contact with respect to the fixed contact as a function of fluid temperature within the capsule and thereby vary the set point level as a function of the air temperature within the tire, said diaphragm operable, under the influence of cavity and tire fluid pressures, for inward and outward excursions with respect to said rigid body portion while in a first contact state, to substantially vary the volume of said cavity as a function of said cavity and tire fluid pressures to virtually effect a preselectable temperature compensation characteristic; and means operative to selectively position the rigid body portion of the capsule with respect to the switch to effect establishment of said set point level

Claim 30

The valve-switch of claim 25 further comprising a plunger disposed between the diaphragm and moving contact.

Claim 31

The valve-switch of claim 25, wherein said rigid body portion and diaphragm are constructed of metal and are formed by welding the adjoining circumferential surfaces thereof.

Claim 32

The valve-switch of claim 25, wherein the pressure within said capsule equals the air pressure in said tire at said set point level.

Claim 35

The method of claim 29, further comprising the step of calibrating said device by selectively repositioning said capsule with respect to said housing under known temperature and pressure conditions.

Claim 36

The method of claim 29, wherein the step of forming said capsule comprises the sub-steps of: forming said rigid wall member to define a capsule pressurizing aperture; forming said compliant wall member; and sealingly engaging said rigid and compliant wall members to define said cavity.

Claim 37

The method of claim 30, wherein the step of sealing said cavity comprises plugging a capsule pressurizing aperture after the fluid within said cavity has been pressurized.

Claim 38

The method of claim 29, wherein said capsule is installed within said housing after said switch means.

Claim 39

The method of claim 29, wherein said capsule is installed within said housing before said switch means.

Claim 40

The method of claim 29, wherein said step of pressurizing fluid within said cavity comprises pressurizing said fluid to a predetermined value which equals said selected level.

Claim 41

The method of claim 31, wherein said capsule is sealed upon engagement of said rigid and compliant wall members.

Claim 42

An improved fluid pressure monitoring switch of the type including a housing adapted for mounting within a container, at least one moving contact and at least one fixed contact both disposed within said housing, said switch operative to monitor the fluid pressure within the container and to shift from a first contact state to a second contact state when the fluid pressure falls below a selected level the improvement comprising: a capsule comprising a structurally rigid element and defining a sealed cavity defined at least in part by a compliant wall member, said cavity pressurized to a predetermined value, means whereby said compliant wall member is operatively engaging said moving contact for displacement with respect to said fixed contact as a function of fluid temperature within said capsule, and thereby varying said selected level as a function of said fluid temperature, whereby said compliant wall member is operable, under the influence of cavity and container fluid pressures for inward and outward excursions with respect to said rigid element while in said first contact state to substantially vary the volume of said cavity as a function of said cavity and container fluid pressures to virtually effect a preselectable temperature compensation characteristic; and capsule retention means operative to maintain said rigid element in a fixed relationship with said housing.

Claim 43

An improved fluid pressure monitoring switch of the type including a housing adapted for mounting within a container, at least one moving contact and at least one fixed contact both disposed within said housing, said switch operative to monitor the fluid pressure within the container and to shift from a first contact state to a second contact state when the fluid pressure falls below a selected level the improvement comprising: a capsule comprising a structurally rigid element and defining a sealed cavity defined at least in part by a compliant wall member, said cavity pressurized to a predetermined value, means whereby said compliant wall member is operatively engaging said moving contact for displacement with respect to said fixed contact as a function of fluid temperature within said capsule, and thereby varying said selected level as a function of said fluid temperature, whereby said compliant wall member is operable, under the influence of cavity and container fluid pressures for inward and outward excursions with respect to said rigid element while in said first contact state to substantially vary the volume of said cavity as a function of said cavity and container fluid pressures to virtually effect a preselectable temperature compensation characteristic; and capsule retention means operative to maintain said rigid element in a fixed relationship with said housing.