Drill feed control

Claim 2

A feed control for use in combination with a drill motor having a drill shaft driving a drill bit, comprising: a frame having means for attachment to the drill motor; a guide shaft having an aft portion axially slidably mounted on the frame for axial extension and retraction parallel to the axis of the drill motor; a pressure foot fixedly mounted on the forward free end of the guide shaft and having a pressure pad to pressurally engage a work piece adjacent to the point of engagement of the drill bit; and restraining means to positively oppose retraction of the guide shaft under axial pressure, the restraining means being controlled in position by the rotation of the drill motor drive shaft to enable the guide shaft and foot to gradually retract with respect to the frame in response to axial pressure between the foot and the work piece and produce a corresponding advance of the drill bit with respect to the pressure foot.

Claim 3

A feed control as claimed in claim 1; the restraining means including a resiliently biased releasable detent connection to permit rapid extension of the guide shaft.

Claim 4

A feed control as claimed in claim 1; and adjustable stop means to limit retraction of the guide shaft and pressure foot to a predetermined extent and consequently limit the penetration of the drill bit into the work piece.

Claim 5

A feed control for use in combination with a drill motor having a drive shaft driving drill bit, comprising; a frame having means for attachment to the drill motor; a guide shaft having an aft portion axially slidably mounted on the frame for extension and retraction movement parallel to the axis of the drill motor; a preSsure foot fixedly mounted on the forward free end of the guide shaft and having a pressure pad to pressurally engage a work piece adjacent to the point of engagement of the drill bit; a lead screw mounted on the frame for rotation about an axis parallel to the axis of the drill motor; drive means connected between the lead screw and the drive shaft of the drill motor to cause rotation only of the lead screw in response to the rotation of the drive shaft and axial pressure on the pressure foot; and detent means connected to the guide shaft and engaging the threads of the lead screw to restrain retraction of the guide shaft under axial pressure; the rotation of the lead screw enabling the detent means and the guide shaft to gradually retract with respect to the frame in response to axial pressure and effectively enable the drill bit to advance with respect to the work piece at a limited feed rate.

Claim 6

A feed control for use in combination with a drill motor having a drive shaft driving drill bit, comprising; a frame having means for attachment to the drill motor; a guide shaft having an aft portion axially slidably mounted on the frame for extension and retraction movement parallel to the axis of the drill motor; a preSsure foot fixedly mounted on the forward free end of the guide shaft and having a pressure pad to pressurally engage a work piece adjacent to the point of engagement of the drill bit; a lead screw mounted on the frame for rotation about an axis parallel to the axis of the drill motor; drive means connected between the lead screw and the drive shaft of the drill motor to cause rotation only of the lead screw in response to the rotation of the drive shaft and axial pressure on the pressure foot; and detent means connected to the guide shaft and engaging the threads of the lead screw to restrain retraction of the guide shaft under axial pressure; the rotation of the lead screw enabling the detent means and the guide shaft to gradually retract with respect to the frame in response to axial pressure and effectively enable the drill bit to advance with respect to the work piece at a limited feed rate.

Claim 7

A feed control as claimed in claim 4; the detent means being resiliently biased into engagement with the lead screw to maintain contact for application of axial pressure, and readily releasable against the biasing force in the absence of axial pressure to permit rapid extension and retraction of the guide shaft.

Claim 8

A feed control as claimed in claim 5; the guide shaft being provided with an axially elongate radially extending cavity; the detent means being in the form of an elongate arm located in the guide shaft cavity and being pivotally mounted at its forward end in the forward portion of the cavity and provided at its aft end with a formation for pressurally engaging the threads of the lead screw.

Claim 9

A feed control as claimed in claim 6; the pivotal mounting of the arm comprising a pivot shaft rotatably mounted in the guide shaft on an axis perpendicular to the axis of the guide shaft; the arm being fixedly connected to the pivot shaft for rotation therewith; and the pivot shaft having one end extending outward of the frame and provided with a formation to be manually gripped for rotation of the pivot shaft and arm.

Claim 10

A feed control as claimed in claim 4; and adjustable stop means interengaging between the pressure foot and the frame to positively limit the extent of retraction of the pressure foot.

Claim 11

A feed control as claimed in claim 4; the detent means being resiliently biased into engagement with the lead screw to maintain contact for application of axial pressure, and readily releasable against the biasing force in the absence of axial retracting pressure; and spring means operable to urge the guide shaft toward fully extended position in the absence of axial retracting pressure.

Claim 12

A feed control as claimed in claim 9; an axial passage in the frame extending parallel to the axis of the guide shaft; a return shaft having a forward end connected to the pressure foot and an aft portion slidably extending into the passage; and a return spring mounted in the passage and contacting the aft end of the return shaft to urge it forward and move the guide shaft and pressure foot toward extended position.

Claim 13

A feed control as claimed in claim 10; and an abutment axially movable in the passage to a forward position engaging the aft end of the spring to place it under compression and to an aft position to unload the spring.

Claim 14

A feed control as claimed in claim 10; the return shaft being threaded; and a stop member threaded on the return shaft and axially adjustable to predetermined positions to engage the frame and limit the retraction of the pressure foot.

Claim 15

A feed control as claimed in claim 4; a spring-loaded shoe on the guide shaft frictionally engaging the frame to prevent unintentional axial movement of the guide shaft in the absence of axial pressure on the work piece.

Claim 16

A feed control as claimed in claim 4; the drive means and the lead screw being provided with normally spaced, relatively axially movable, cooperating clutch members; thE lead screw being axially movable to a limited extent with the guide shaft and nut member in response to axial retraction pressure from engagement with the work piece to engage the clutch members and cause rotation of the lead screw in response to rotation of the drill motor drive shaft.

Claim 17

A feed control as claimed in claim 14; and spring means operative to urge the lead screw axially to a position to disengage the clutch members when axial pressure on the work piece is released.

Claim 18

A feed control as claimed in claim 4; the drive means including a plurality of interengaging driving and driven gears; an extension shaft mounted at its aft end on the drill motor drive shaft and carrying a drill bit chuck at its forward end; and the first driving gear of the drive means being fixedly mounted on the extension shaft for rotation therewith.

Claim 19

A feed control as claimed in claim 4; the pressure pad being provided with a plurality of spaced sharp prongs extending from its work face to penetratingly engage a soft work piece and prevent lateral slippage.

Claim 20

A feed control as claimed in claim 4; further including a supporting base adapted to be mounted on a work holding fixture; the frame and an attached drill motor being slidably mounted on the base for axial movement toward and away from a work piece to be drilled; and fluid power means to yieldably force the frame and drill motor toward the work piece.

Claim 21

A feed control as claimed in claim 4; further including a supporting base provided with clamping means for rigidly connecting it to a work piece assembly; the frame and an attached drill motor being slidably mounted on the base for axial movement toward and away from the assembly; and fluid power means to yieldably force the frame and drill motor toward the assembly.

Claim 22

A feed control for use in combination with a drill motor having a drive spindle, an axially movable drive shaft for driving a drill bit, and clutch means between the drive spindle and drive shaft engageable by relative retraction of the drive shaft, comprising: a frame having means for attachment to the drill motor; a guide shaft having an aft portion slidably mounted on the frame for axial extension and retraction parallel to the axis of the drive shaft; a pressure foot fixedly mounted on the forward free end of the guide shaft and having a pressure pad to pressurally engage a work piece adjacent to the point of engagement of the drill bit; and restraining means to positively oppose retraction of the guide shaft under axial pressure; the restraining means being controlled in position by the rotation of the drive shaft to enable the guide shaft and foot to gradually retract with respect to the frame in response to axial pressure between the foot and the work piece and produce a corresponding advance of the drill bit with respect to the pressure foot; the drive shaft being driven by the drive spindle only through engagement of the clutch means in response to retraction of the drive shaft under axial pressure; the clutch means being releasable in response to cessation of such axial pressure to discontinue both rotation of the drive shaft and drill bit and retraction of the pressure foot.

Claim 23

A feed control for use in combination with a drill motor having a drive spindle, an axially movable drive shaft for driving a drill bit, and clutch means between the drive spindle and drive shaft engageable by relative retraction of the drive shaft, comprising: a frame having means for attachment to the drill motor; a guide shaft having an aft portion slidably mounted on the frame for axial extension and retraction parallel to the axis of the drive shaft; a pressure foot fixedly mounted on the forward free end of the guide shaft and having a pressure pad to pressurally engage a work piece adjacent to the point of engagement of the drill bit; and restraining means to positively oppose retraction of the guide shaft under axial pressure; the restraining means being controlled in position by the rotation of the drive shaft to enable the guide shaft and foot to gradually retract with respect to the frame in response to axial pressure between the foot and the work piece and produce a corresponding advance of the drill bit with respect to the pressure foot; the drive shaft being driven by the drive spindle only through engagement of the clutch means in response to retraction of the drive shaft under axial pressure; the clutch means being releasable in response to cessation of such axial pressure to discontinue both rotation of the drive shaft and drill bit and retraction of the pressure foot.

Claim 24

A feed control as claimed in claim 20; and spring means arranged to bias the clutch means to normally disengaged condition.

Claim 25

A feed control as claimed in claim 20; the restraining means including second clutch means biased to normally disengaged condition to immobilize the restraining means and engageable in response to axial pressure on the pressure foot to activate the restraining means for retraction of the guide shaft.

Claim 26

A feed control for use in combination with a drill motor having a drive shaft driving a drill bit, comprising: a frame having means for attachment to the drill motor; a guide shaft having an aft portion axially slidably mounted on the frame for axial extensIon and retraction parallel to the axis of the drill motor; a pressure foot fixedly mounted on the forward free end of the guide shaft and having a pressure pad to pressurally engage a work piece adjacent to the point of engagement of the drill bit; and restraining means to positively oppose retraction of the guide shaft under axial pressure, the restraining means being controlled in position in a timed relation with the rate of rotation of the drill motor shaft to enable the guide shaft and foot to gradually retract with respect to the frame in response to axial pressure between the foot and the work piece and produce a corresponding advance of the drill bit with respect to the pressure foot.

Claim 27

A feed control for use in combination with a drill motor having a drive shaft driving a drill bit, comprising: a frame having means for attachment to the drill motor; a guide shaft having an aft portion axially slidably mounted on the frame for axial extensIon and retraction parallel to the axis of the drill motor; a pressure foot fixedly mounted on the forward free end of the guide shaft and having a pressure pad to pressurally engage a work piece adjacent to the point of engagement of the drill bit; and restraining means to positively oppose retraction of the guide shaft under axial pressure, the restraining means being controlled in position in a timed relation with the rate of rotation of the drill motor shaft to enable the guide shaft and foot to gradually retract with respect to the frame in response to axial pressure between the foot and the work piece and produce a corresponding advance of the drill bit with respect to the pressure foot.