Impactor drill tool

A drilling apparatus for attachment to an impact tool of the type having a hammer reciprocally carried within a carriage:

• a housing;
• mounting means for mounting the housing to the carriage;
• a tappet reciprocally carried in the housing for receiving blows from the hammer;
• means for preventing the tappet from rotating with respect to the housing;
• a tool shank reciprocally and rotatably carried in the housing for receiving blows from the tappet, the tool shank having an upper end containing a plurality of inclined splines and a lower end adapted to receive a bit;
• a sleeve reciprocally carried in the housing and having an inner bore with a plurality of inclined splines that engage the inclined splines of the tool shank;
• clutch means for locking the sleeve to the tappet when the tappet is moving downward, causing the splines of the sleeve to move down the splines of the tool shank to rotate the tool shank;
• and
• spring means for moving the sleeve and the tappet upward from the tool shank after impact of the tappet with the tool shank;
• the clutch means including means for allowing the sleeve to rotate with respect to the tappet as the sleeve moves upward.

A drilling attachment for an impact tool of the type having a hammer reciprocally carried within a carriage, comprising:

• a housing adapted to be mounted to the carriage;
• a tappet carried in the housing for receiving blows from the hammer, the tappet having a depending lower end encircled by a downwardly facing shoulder, the lower end having a plurality of vertical splines;
• means for preventing the tappet from rotating with respect to the housing;
• a sleeve reciprocally carried in the housing and having an upper bore and a lower bore of lesser diameter than the upper bore and divided by a upwardly facing shoulder, the upper bore having a plurality of vertical splines, the lower bore having a plurality of inclined splines;
• at least one tappet disk carried between the shoulders, having an aperture for receiving the lower end of the tappet, the aperture having a plurality of tabs for engaging the vertical splines of the tappet;
• at least one sleeve disk carried between the shoulders and having an aperture for receiving the tappet lower end, the sleeve disk having a periphery with a plurality of tabs for engaging the vertical splines of the sleeve, the tappet disk and sleeve disk adapted to be pressed between the shoulders during downward movement of the tappet to frictionally lock the sleeve to the tappet;
• a tool shank reciprocally and rotatably carried in the housing for receiving blows from the tappet, the tool shank having a lower end adapted to receive a bit and an upper end with a plurality of inclined splines that engage the inclined splines of the sleeve for rotation of the tool shank during downward movement of the tappet;
• and
• a helical spring compressed between the housing and the sleeve for urging the sleeve upward;
• the sleeve disk being adapted to rotate with respect to the tappet disk during upward movement of the tappet, when pressure between the shoulders is reduced.