Abstract: Dial-type flow-restriction gauges are used for indicating flow-restriction conditions of fluid filters, such as automobile air and fuel filters. Prior versions of these type filters have been more complicated and costly to manufacture than desirable. Accordingly, the present inventors have devised, among other things, an exemplary dial-type flow-restriction gauge that is inexpensive to manufacture and performs reliability and consistently over a wide temperature range. One exemplary gauge includes an external dial that rotates relative a restriction scale in response to a differential pressure. Placement of the dial on the exterior of the gauge eliminates the need to use clear material and allows embedding of the restriction scale into an exterior surface of the gauge.

Abstract: Dial-type flow-restriction gauges are used for indicating flow-restriction conditions of fluid filters, such as automobile air and fuel filters. Prior versions of these type filters have been more complicated and costly to manufacture than desirable. Accordingly, the present inventors have devised, among other things, an exemplary dial-type flow-restriction gauge that is inexpensive to manufacture and performs reliability and consistently over a wide temperature range. One exemplary gauge includes an external dial that rotates relative a restriction scale in response to a differential pressure. Placement of the dial on the exterior of the gauge eliminates the need to use clear material and allows embedding of the restriction scale into an exterior surface of the gauge.

Abstract: Dial-type flow-restriction gauges are used for indicating flow-restriction conditions of fluid filters, such as automobile air and fuel filters. Prior versions of these type filters have been more complicated and costly to manufacture than desirable. Accordingly, the present inventors have devised, among other things, an exemplary dial-type flow-restriction gauge that is inexpensive to manufacture and performs reliability and consistently over a wide temperature range. One exemplary gauge includes an external dial that rotates relative a restriction scale in response to a differential pressure. Placement of the dial on the exterior of the gauge eliminates the need to use clear material and allows embedding of the restriction scale into an exterior surface of the gauge.

Abstract: An indicator suitable for signaling restricted flow of a fluid through a filter mounted in a filter indicator includes a housing having an inner cavity. A diaphragm disposed within the housing separates the inner cavity into first and second chambers and deflects from a neutral position in response to applied pressures within the first and second chambers. A tab assembly opposite the diaphragm includes a spring-loaded flag moveable from a first position within the housing to a second position outside the housing. A pin operably coupled to the diaphragm holds the spring-loaded flag within the housing when the diaphragm is in the neutral position. In response to the diaphragm being deflected sufficiently from the neutral position to release the pin, the spring-loaded flag travels to the second position outside of the housing, thereby indicating a restrictive flow condition for the filter.

Abstract: An indicator suitable for signaling restricted flow of a fluid through a filter mounted in a filter assembly includes a housing having an inner cavity. A diaphragm disposed within the housing separates the inner cavity into first and second chambers and deflects from a neutral position in response to applied pressures within the first and second chambers. A tab assembly opposite the diaphragm includes a spring-loaded flag moveable from a first position within the housing to a second position outside the housing. A pin operably coupled to the diaphragm holds the spring-loaded flag within the housing when the diaphragm is in the neutral position. In response to the diaphragm being deflected sufficiently from the neutral position to release the pin, the spring-loaded flag travels to the second position outside the housing, thereby indicating a restricted flow condition for the filter.