Lubricating system for multi-spindle revolving head mechanism

In a multiple-spindle mechanism, including a housing having a forward journal portion with a circular internal bearing surface;

• a revolving head mounted for rotation in said housing, said head comprising a front plate having a circumferential external bearing surface in contact with said internal bearing surface of said housing and defining a machining zone outwardly thereof, and a multiplicity of spindle bearings mounted at locations spaced about said front plate, each of said spindle bearings having a cylindrical internal bearing surface;
• a multiplicity of spindles, each rotatably mounted in an associated one of said spindle bearings and having a cylindrical external bearing surface in contact with said internal bearing surface of said associated bearing;
• and means for supplying lubricant substantially between all of said bearing surfaces that are in mutual contact;
• wherein the improvement comprises a system in which said head has a continuous groove formed into said circumferential external bearing surface of said front plate;
• said front plate and said spindle bearings have a multiplicity of ducts and ports therein, respectively, operatively connecting said internal bearing surfaces of said spindle bearings to said groove;
• said housing has a passage therein for communicating with said means for supplying and opening at said circumscribing groove of said head;
• and said means for supplying is adapted to supply an air suspension of lubricant under pressure to said passage, said mutually contacting bearing surfaces opening to said machining zone, and said head being substantially devoid of means providing mechanical seals for preventing the passage of lubricant into said zone from between said mutually contacting bearing surfaces.