Drill

A pneumatic-hydraulic drill comprising:

• a main housing having a front end and a rear end with an opening extending therethrough from the front end to the rear end;
• a hydraulically activated feed cylinder external to said main housing and adjacent to the rear end of said housing, said feed cylinder including a cylinder having a forward end and a rear end and having a central bore that is substantially parallel to said opening of said main housing, said feed cylinder further including an outer piston having an axial bore that extends forwardly from said outer piston, said outer piston at least partially disposed within said feed cylinder, said outer piston configured for axial movement within the central bore of said cylinder;
• a pneumatically activated motor, said motor being configured to fit within the opening of said housing, said motor having a forward end and a rear end, said rear end of said motor being attached to the forward end of the rod of said feed cylinder, said axial bore of said outer piston being in fluid communication with said motor to supply pressurized air to said motor, said motor being movable between a rearmost position wherein the outer piston of said feed cylinder is in a retracted position and a forwardmost position wherein the outer piston of said feed cylinder is in said extended position;
• a drill spindle assembly comprising a drill spindle and a planet gear carrier, said drill spindle having a front end and rear end and adapted to receive a drill bit in said front end, said drill spindle extending from the opening of said main housing at the front end of said housing, said planet gear carrier connected to the forward end of said pneumatically activated motor and adapted to rotate in response to the activation of said pneumatically activated motor whereby said drill spindle is also rotated, wherein said drill spindle assembly comprises a one-piece structure having a rear end and a front end, the rear end of the drill spindle assembly extending from the forward end of said pneumatically activated motor, the front end of said drill spindle assembly configured to receive said drill bit for drilling a hole and extending beyond the front end of said main housing, wherein the drill spindle of the drill spindle assembly is integral with the planet gear carrier of the drill spindle assembly thereby eliminating a joint between said drill spindle and said planet gear carrier to improve the precision and accuracy of a drilled hole;
• a hydraulic pump assembly comprising a fluid reservoir, a rotary gerotor pump, and an air motor, the fluid reservoir being disposed at a rearward end of the hydraulic pump assembly and defining a storage and separation chamber for allowing air bubbles to separate from the hydraulic fluid, a reservoir fill port opening to the storage and separation chamber for adding hydraulic fluid to the chamber, a filter disposed between the reservoir fill port and the fluid reservoir, a bleed port positioned at a rearward end of the fluid reservoir which allows any air separated from the hydraulic fluid in the chamber to exit the reservoir, a snorkel surrounded by a join plate and connecting the fluid reservoir to the rotary gerotor pump, the snorkel for delivering fluid to the rotary gerotor pump, the rotary gerotor pump actuated by a first air motor connected thereto and used for pressurizing hydraulic fluid for delivery to the feed cylinder, the rotary gerotor pump comprises a gerotor assembly having a gear assembly comprising a first gear with external gear teeth and a second gerotor gear having internal teeth which cooperate with the teeth of the first gear of the gerotor assembly such that air from the first air motor is prevented from leaking into the hydraulic fluid used by the rotary gerotor pump, an outer housing surrounding the rotary gerotor pump, a drive shaft coupled to the rotary gerotor pump when the outer housing, the drive shaft being supported by a bearing at a rearward end of the drive shaft, a seal configured around the drive shaft for preventing pressurized air from the air motor from mixing with hydraulic fluid from the rotary gerotor pump, the rotary gerotor pump connected to and actuated by the air motor, wherein the hydraulic pump assembly prevents leaking of air into the hydraulic fluid of the drill;
• a first valve system for controlling the operation of said drill;
• a first circuit for supplying air from a source of pressurized air to the axial bore of the outer piston of said feed cylinder, to said rotary gerotor pump, and to said first valve system, wherein said first circuit includes an automatic cycle circuit whereby said trigger is held in a depressed position until the drill completely drills a hole in a workpiece, and further when the drill is retracted from the hold, said automatic cycle prevents turning of the drill;
• a second circuit for supplying pressurized hydraulic fluid to said feed cylinder and to said first valve system;
• and
• a clamping assembly for clamping the drill to a workpiece having a front end and a rear end with the front end of the clamping assembly closer to the workpiece than the rear end of the clamping assembly, the clamping assembly comprising a hydraulically activated clamp feed cylinder, the clamp feed cylinder connected to the rear end of the clamp assembly and axially aligned with the clamping assembly, the clamp feed cylinder having a cylinder with a bore, the cylinder having a forward end and a rear end, the clamp feed cylinder also comprises a piston and a puller that are disposed in the bore of the clamp feed cylinder and the piston and rod configured for axial movement within the bore of the clamp feed cylinder, the clamping assembly further comprising a collet having an axial bore with a pilot disposed therein, the pilot fixed to the puller of the clamp feed cylinder with the movement of the pilot within the collet in a forward and rearward direction being controlled by the forward and rearward movement of the puller of the clamp feed cylinder, wherein the collet and the pilot are moved simultaneously by the clamp feed cylinder and wherein the collet and the pilot are in axial tension when the drill is clamped to the workpiece such that said collet and said pilot act as a single tension member.