초록 ▼

A filter head adapted for use with spin-on filters is shown. The filter head carries a spring load piston which is normally biased to close a filter bypass channel. A fluid pressure increase caused by a clogged filter causes the piston to move opening the bypass and at the same time opening a signal

A filter head adapted for use with spin-on filters is shown. The filter head carries a spring load piston which is normally biased to close a filter bypass channel. A fluid pressure increase caused by a clogged filter causes the piston to move opening the bypass and at the same time opening a signal channel between a source of fluid pressure and a signal outlet.

대표청구항 ▼

A filter head for receiving a filter and mounting to an end of a spin-on type filter having a central fluid outlet and fluid inlet extending circumferentially around the central fluid outlet, the filter head including a pressure isolation valve for emitting a pressure signal when the pressure differ

A filter head for receiving a filter and mounting to an end of a spin-on type filter having a central fluid outlet and fluid inlet extending circumferentially around the central fluid outlet, the filter head including a pressure isolation valve for emitting a pressure signal when the pressure differential across the filter head reaches a predetermined value, comprising: a filter head; means for mounting the spin-on type filter to the filter head housing; an upstream fluid passageway connecting the filter head housing with the filter circumferential fluid inlet and communicating to a source of unfiltered fluid; a downstream fluid passageway connecting the filter head with the filter central fluid outlet and communicating with an outlet for filtered fluid; means for sensing the difference in pressure between the fluid in the upstream and downstream fluid passageways, wherein the sensing means includes a cylindrical piston slidably mounted in a cylindrical chamber formed in the filter head, said chamber having a first fluid inlet formed therein at one end thereof fluidly open to the upstream passageway and a second fluid inlet formed in a sidewall thereof fluidly communicating to the downstream passageway, the piston having first and second faces fluidly communicating with the upstream and downstream passageways through the first and second fluid inlets, respectively, wherein the piston includes a cylindrical Wall, Said piston having a recessed portion formed in the cylindrical wall extending annularly around the piston and defining an annular chamber with said chamber, and biasing means for exerting a force of a predetermined value on the piston and biasing the piston against fluid pressure in the upstream passageway; a signal channel opening to a first signal aperture formed in the sidewall of said chamber axially between said first and second fluid inlets for fluidly connecting the upstream fluid passageway with the chamber; a signal outlet port opening to a second signal aperture formed in the sidewall of said chamber axially between said first and second fluid inlets for fluidly connecting the chamber to a pressure switch; wherein the cylindrical wall of said piston includes a cylindrical un-recessed portion that is configured and arranged to sealably cover said first and second signal apertures to substantially prevent flow through said first and second apertures when said piston is in a closed position; wherein said recess is configured and arranged to be adjacent said first and second signal apertures to permit flow from said first signal aperture to said second signal aperture via said recess when said piston is in an open position; wherein the biasing means moves the piston to said closed position when the sensing means senses a difference between the pressures in the upstream and downstream passageways that is less than the predetermined value; and, wherein fluid pressure from the upstream passageway moves the piston to said open position wherein when the sensing means senses a difference between the pressures in the upstream and downstream passageways that equals or exceeds the predetermined value.