Pressure gauge assembly

A pressure indicator gauge for an aircraft tire comprising;

• means for attachment of the gauge to the tire;
• sensor means for sensing a pressure differential in fluidic contact with the pressurized fluid in the tire;
• means for compensating for volumetric changes in the tire volume during normal operation including a secondary source of pressure operatively connected to the sensor means and having a predetermined pressure relative to the tire pressure to compensate for any volumetric changes in the tire during operation, and
• indicator output means responsive to the sensor means for providing an output representation of any pressure differential between the secondary source of pressure and the tire that would indicate an underinflated tire.

A pressure indicator gauge comprising;

• means for attachment of the gauge to a first source pressure to be monitored;
• a bourdon tube sensing element for sending a pressure differential in fluidic contact with the pressurized fluid in the first pressure source;
• a secondary source of pressure also operatively in fluidic contact with the bourdon tube sensing element whereby both the interior and exterior surfaces of the bourdon tube sensing element are subject to pressure above atmospheric, wherein the secondary source of pressure is pressure charged approximately five to ten percent less than the pressure charge of the first source pressure at atmospheric pressure and 68.degree. F., and
• means for indicating any movement of the bourdon tube sensing element in response to a pressure differential between its interior and exterior surfaces.

A temperature compensated pressure indicator for determining any fluidic leaks from a pressurized storage container of fluid comprising;

• means for attachment of the pressure indicator to the storage container;
• bourdon coil sensor means for sensing a pressure differential in fluidic contact with the storage container;
• a secondary source of pressure operatively connected to the same bourdon coil sensor means having substantially the same pressure temperature response characteristics as the fluid in the storage container;
• a magnetic force field generating member operatively connected to the response of the sensor means,
• indicator output means responsive to the magnetic force field generating member for providing an output representation of any pressure differential between the secondary source of pressure and the storage container and
• means for compensating for volumetric changes in the storage container volume including connecting the secondary source of pressure to the interior of the bourdon coil, the secondary source of pressure being undercharged approximately five to ten percent below the pressure charge in the storage container at approximately 14.7 psia and 68.degree. F.

A hermetically sealed pressure indicator gauge comprising;

• means for attachment of the gauge to a first source pressure to be monitored;
• a bourdon tube sensing element for sensing a pressure differential in fluidic contact with the pressurized fluid in the first pressure source;
• a secondary source of pressure also operatively in fluidic contact with the bourdon tube sensing element whereby both the interior and exterior surfaces of the bourdon tube sensing element are subject to pressure above atmospheric;
• means for hermetically sealing the bourdon tube sensing element and secondary source of pressure to prevent any loss of the first source of pressure if either one of the bourdon tube sensing element and secondary source of pressure develops a leak, and
• means for indicating any movement of the bourdon tube sensing element in response to a pressure differential between its interior and exterior surfaces further including means for indicating a defective gauge.

A combination pressure indicator and valve assembly for aircraft tires comprising;

• means for attachment of the assembly to a wheel mounting member including a housing assembly;
• sensor means for sensing a pressure differential in fluidic contact with the pressurized fluid in the tire;
• a secondary source of pressure operatively connected to the sensor means having substantially the same pressure temperature response characteristic as the fluid in the tire;
• indicator output means responsive to the sensor means for providing an output representation of a predetermined pressure differential between the secondary source of pressure and the tire pressure,
• the indicator output means includes a first magnet operatively mounted to the sensor means and mounted within the housing assembly and a second magnet mounted externally of the housing assembly and responsive to the position of the first magnet, and
• valve means for providing fluidic access to the interior of the tire.

A hermetically sealed pressure indicator gauge comprising;

• means for attachment of the gauge to a first source pressure to be monitored;
• a bourdon tube sensing element for sensing a pressure differential in fluidic contact with the pressurized fluid in the first pressure source;
• a secondary source of pressure also operatively in fluidic contact with the bourdon tube sensing element whereby both the interior and exterior surfaces of the bourdon tube sensing element are subject to pressure above atmospheric, the secondary source of pressure is pressure charged approximately five to ten percent less than the pressure charge of the first source pressure at atmospheric pressure and 68.degree. F;
• means for hermetically sealing the bourdon tube sensing element and secondary source of pressure to prevent any loss of the first source of pressure if either one of the bourdon tube sensing element and secondary source of pressure develops a leak, and
• means for indicating any movement of the bourdon tube sensing element in response to a pressure differential between its interior and exterior surfaces.