Adjustable dual bit drilling machine

A dual bit drilling machine comprising, in combination,

• a pair of spaced-apart drill bit receiving spindles,
• a housing defining a respective pair of apertures for rotatably receiving said pair of spindles,
• a first cylinder defined by said housing, a first piston slidably disposed in said first cylinder and coupled to a first piston rod,
• a second cylinder defined by said housing, a second piston slidably disposed in said second cylinder and coupled to a second piston rod,
• a baseplate disposed adjacent said housing and coupled to said second piston rod,
• an expandable collect disposed in said baseplate and having a mandrel disposed therein, said mandrel operably coupled to said first piston rod, and
• pneumatic control means for providing compressed air to said first and said second cylinders for sequentially expanding said collet and advancing said spindles and retracting said spindles and collapsing said collet.

A dual bit drilling assembly comprising, in combination,

• a pair of spaced-apart drill bit receiving spindles,
• a first housing defining a first aperture for rotatably receiving one of said pair of spindles,
• a second housing adjustably secured to said first housing and defining a second aperture for rotatably receiving the other of said pair of spindles,
• a first cylinder defined by said housing, a first piston slidably disposed in said first cylinder and coupled to a first piston rod,
• a second cylinder defined by said housing, a second piston slidably disposed in said second cylinder and coupled to a second piston rod,
• a baseplate disposed adjacent said housing and coupled to said second piston rod,
• an expandable collet extending through said baseplate and having a mandrel disposed therein, said mandrel operably coupled to said first piston rod, and
• control means for providing compressed air to said first and said second cylinders for sequentially expanding said collet and advancing said spindles and retracting said spindles and collapsing said collet.

A control assembly for a drilling apparatus, comprising, in combination,

• valve means for initiating an operating cycle,
• a two state shuttle valve defining a first and a second end and having a first, advance state and a second, retract state,
• a pulse valve having an input in fluid communication with said valve means and an output in fluid communication with one end of said shuttle valve for disposing said shuttle valve in said first state when said valve means is activated,
• a housing defining a first cylinder in fluid communication with said shuttle valve and a second cylinder in fluid communication with said shuttle valve, said first cylinder having a first piston slidably disposed therein and said second cylinder having a second piston slidably disposed therein,
• a baseplate disposed adjacent said housing and operably coupled to said first piston, a collet assembly including a mandrel operably coupled to said second piston and extending through said baseplate,
• a vent in fluid communication with said second end of said shuttle valve,
• stop means coupled to said baseplate for closing said vent and disposing said shuttle valve in said second, retract state,
• whereby said second piston translates to expand said collet and said first piston translates said baseplate toward said housing when said shuttle valve is in said first state and said first piston translates said baseplate away from said housing and said second piston translates to collapse said collet when said shuttle valve is in said second state.

A dual bit drilling machine comprising, in combination,

• a pair of spaced-apart spindles adapted to receive a respective pair of drill bits,
• means for driving said pair of spaced-apart spindles,
• a first housing including means for rotatably receiving one of said spindles along a first axis,
• a second housing including means for rotatably receiving the other of said spindles along a second axis parallel to said first axis,
• means for pivotally coupling said second housing to said first housing along a third axis parallel to and spaced from said first axis, and
• means for maintaining a selected position of said second housing relative to said first housing.