Drill head unit

A drill head unit for transmitting rotational power from a horizontally oriented motor to a vertically oriented hollow drill bit comprising:

• a housing having a first cavity herein for enclosing a gear assembly,
• a first bevel gear mounted in said first cavity and journaled for rotation about a vertical axis,
• means for mounting a drill chuck on said first bevel gear, said means for mounting including an axial opening for retaining a drill chuck therein,
• a first shaft extending downwardly below said first bevel gear, said first shaft having an axial hole communicating with said axial opening in said means for mounting,
• means for transferring rotational power from said first bevel gear to a drill chuck in said means for mounting,
• a second cavity in said housing below said first bevel gear, said second cavity being in communication with said axial hole in said first shaft,
• said housing having a port opening into said second cavity through which a fluid may flow,
• a bevel pinion mounted in said first cavity and journaled for rotation about a horizontal axis, said bevel pinion being adapted to engage said first bevel
• attachment means for attaching said bevel pinion to a motor shaft,
• first sealing means for sealing said first gear against said housing,
• second sealing means for sealing said second gear against said housing,
• said housing having an opening therein,
• a cartridge removably fitted into said housing opening, and removable in a direction away from said means for mounting,
• a sealing surface on one of said first shaft and said cartridge, and
• a seal for sealing said first cavity from said second cavity fitted on the other of said first shaft and said cartridge, said seal sealing against said sealing surface.

A drill head unit for transmitting rotational power from a motor to a vertically oriented drill bit comprising:

• a housing having a first cavity therein for enclosing a gear assembly,
• a first gear mounted in said first cavity and journaled for rotation about a vertical axis,
• means for mounting a drill chuck on said first gear, said means for mounting having an axial opening therethrough for retaining a drill chuck therein,
• a first shaft extending downwardly below said first gear, said first shaft having an axial hole communicating with said axial opening in said means of mounting,
• a drill chuck fitted into said axial opening of said means for mounting, said drill chuck having a plurality of spaced lobes around a circumference thereof, each of said lobes having a crest,
• said opening of said means for mounting having a plurality of recesses which are complementary in shape to said plurality of lobes around said circumference of said drill chuck,
• said opening in said means for mounting having spaced contact areas and relief areas, said contact area positioned to exert rotational force to said drill chuck at positions having an angle of between about 8 degrees and about 30 degrees from said crest of each of said lobes,
• a second cavity in said housing below said first gear, said second cavity being in communication with said axial opening in said means for mounting,
• said housing having a port opening into said second cavity through which a fluid may flow,
• a second gear mounted in said first cavity,
• attachment means for attaching said second gear to a motor shaft,
• first sealing means for sealing said first gear against said housing,
• second sealing means for sealing said second gear against said housing,
• said housing having an opening therein,
• a cartridge removably fitted into said housing opening,
• a sealing surface on one of said first shaft and said cartridge, and
• a seal for sealing said first cavity from said second cavity fitted on the other of said first shaft and said cartridge, said seal sealing against said sealing surface.

A drill head unit for transmitting rotational power from a motor to a vertically oriented drill bit comprising:

• a housing having a first cavity therein for enclosing a gear assembly,
• a first gear mounted in said first cavity and journaled for rotation about a vertical axis,
• means for mounting a drill chuck on said first gear, said means for mounting having an axial opening therethrough for retaining a drill chuck therein,
• a drill chuck fitted into said axial opening of said means for mounting, said drill chuck having a plurality of spaced lobes around a circumference thereof, each of said lobes having a crest,
• said opening of said means for mounting having a plurality of recesses which are complementary in shape to said plurality of lobes around said circumference of said drill chuck for receiving said drill chucks,
• said opening in said means for mounting having spaced contact areas and relief areas, said contact areas positioned to exert rotational force to said drill chuck at positions having an angle of between about 8 degrees and about 30 degrees from said crest of each of said lobes,
• a second gear mounted in said first cavity,
• attachment means for attaching said second gear to the shaft of a motor,
• first sealing means for sealing said first gear against said housing,
• second sealing means for sealing said second gear against said housing.