Air-filtering hydraulic reservoir breather cap

A breather cap for an oil reservoir, said breather cap being positioned over an oil reservoir outlet having the shape of a cylindrical bore, said breather cap receiving high-velocity air containing suspended droplets of oil, said breather cap separating the oil from said air, which is then vented to the atmosphere, said breather cap comprising:

• a housing defining an outer shell of said breather cap, said housing being separated into two portions, comprising an upper portion and a lower portion;
• cylindrical attachment means disposed within a central portion of said housing for affixing said breather cap to said oil reservoir outlet, said cylindrical attachment means comprising a cylindrical coil spring for providing a compressive biasing between said outlet and said housing for maintaining a snug fit therebetween;
• an upright, cup-shaped deflection means having a substantially flat, disc-like mid-section disposed within a mid-portion of said housing over said oil reservoir outlet, said upright, cup-shaped deflection means delineating said upper portion of said breather cap from said lower portion, said upright, cup-shaped deflection means for receiving and slowing said high-velocity air containing said suspended droplets of oil, said high-velocity air impinging upon said substantially flat, disc-like mid-section and being caused to slow its velocity, thereby causing said suspended droplets of oil to separate therefrom, deposit, and aggregate upon said substantially flat, disc-like section, said oil droplets thereafter dripping back into said oil reservoir, and the substantially oil-free air then flowing to a periphery of said substantially flat, disc-like section, and thereafter rising upwards into said upper portion of said housing;
• means defining a narrow, annular passage disposed between said housing and said upright, cup-shaped deflection means, wherein said substantially oil-free air is caused to rise upwards into said upper portion of said housing;
• filtering means disposed within said cylindrical attachment means for assisting in the separation of said suspended droplets of oil from said high-velocity air prior to the impinging thereof upon said substantially flat, disc-like mid-section;
• and
• venting means supported in said upper portion of said housing for allowing said substantially oil-free air to flow out of and vent from said housing.

A breather cap for an oil reservoir, said breather cap being positioned over an oil reservoir outlet having the shape of a cylindrical bore, said breather cap receiving high-velocity air containing suspended droplets of oil, said breather cap separating the oil from said air, which is then vented to the atmosphere, said breather cap comprising:

• a housing defining an outer shell of said breather cap, said housing being separated into two portions, comprising an upper portion and a lower portion;
• cylindrical attachment means disposed within a central portion of said housing for affixing said breather cap to said oil reservoir outlet, said cylindrical attachment means comprising a cylindrical coil spring for providing a compressive biasing between said outlet and said housing for maintaining a snug fit therebetween;
• a cup-shaped deflection means having a substantially flat, disc-like mid-section disposed within a mid-portion of said housing over said oil reservoir outlet, said cup-shaped deflection means delineating said upper portion of said breather cap from said lower portion, said cup-shaped deflection means for receiving and slowing said high-velocity air containing said suspended droplets of oil, said high-velocity air impinging upon said substantially flat, disc-like mid-section and being caused to slow its velocity, thereby causing said suspended droplets of oil to separate therefrom, deposit, and aggregate upon said substantially flat, disc-like section, said oil droplets thereafter dripping back into said oil reservoir, and the substantially oil-free air then flowing to a periphery of said substantially flat, disc-like section, and thereafter rising upwards into said upper portion of said housing;
• means defining a narrow, annular passage disposed between said housing and said cup-shaped deflection means, wherein said substantially oil-free air is caused to rise upwards into said upper portion of said housing;
• filtering means disposed within said cup-shaped deflection means and said housing for assisting in the separation of said suspended droplets of oil from said high-velocity air after said impinging thereof upon said substantially flat, disc-like mid-section;
• and
• venting means supported in said upper portion of said housing for allowing said substantially oil-free air to flow out of and vent from said housing.