Mounting head with safety shut-off valve for replaceable filter cartridge

A mounting head for receiving a replaceable filter cartridge enclosing a filter medium and having at one end concentric entrance and exit passages confined within an axially outwardly projecting annular wall and a concentric, axially outwardly projecting hollow stem, respectively, and said filter cartridge also having radially outwardly projecting mounting means disposed on said annular wall for securing and locking said filter cartridge to said mounting head,

• said mounting head comprising, in combination,
• means defining inlet and outlet ports in said mounting head and inlet and outlet passages connected thereto for communicating fluid respectively to and from said entrance and exit passages of said filter cartridge,
• an outer cavity and an intermediate cylindrical recess formed in said mounting head for sealingly receiving said annular wall of said filter cartridge therein, said mounting head inlet passage communicating with said cylindrical recess,
• a hollow inner sleeve having a central bore disposed concentrically within said cylindrical recess, said central bore communicating with said mounting head outlet passage and being dimensioned and disposed to sealingly receive said hollow stem of said filter cartridge therein,
• circumferentially disposed mounting means located in said outer cavity for cooperating with said filter cartridge mounting means for permitting quick locked connection and unlocked disconnection of said filter cartridge to and from said mounting head incident to axial rotation of said filter cartridge in opposite directions, respectively, relative to said mounting head,
• and valve means disposed in said inlet passage, said valve means being biased to a normally closed position and adapted to be opened incident to axial rotation of said filter cartridge into fully locked connection with said mounting head.