Patent ID: 7470360

Claim:
An indicator suitable for signaling restricted flow of a fluid through a filter mounted in a filter assembly, the indicator comprising: a housing having an inner cavity; a deflectable diaphragm disposed within the housing and separating the inner cavity into first and second chambers with a generally fluid-tight seal, wherein the first chamber is adapted to be in fluid communication with the filter assembly, wherein the diaphragm is deflectable from a neutral position in response to applied pressures within the first and second chambers; a tab assembly having a hole through the tab assembly, the tab assembly including a flag moveable along a first axis from a first position wherein the flag is within the housing and a second position wherein the flag extends from the housing, the tab assembly opposite the diaphragm from the first chamber; a guide plate disposed in the second chamber between the diaphragm and the tab assembly; a pin operably coupled to the diaphragm and protruding along a second axis from the diaphragm into the hole and through the tab assembly when the diaphragm is in at least the neutral position, wherein the second axis is generally perpendicular to the first axis and the guide plate includes a guide plate hole receiving the pin; and wherein the tab assembly includes a reset spring acting against the guide plate and the flag and wherein the tab assembly is biased in the first position with the reset spring and urged toward the second position and wherein movement of the flag from the first position to the second position is actuated in response to the diaphragm being deflected a selected amount from the neutral position into the first chamber and the pin being removed from the tab assembly.