Apparatus for expanding holes

Claim 2

Apparatus for enlarging the diameter of subsurface holes comprising: a tool body adapted to be secured to a drill string; walls defining a bore in the tool body having an open end and another end in flow communication with a fluid carrying portion of the drill string; a piston axially movable in the bore and provided with a skirt portion; means for limiting the axial movement of the piston in the bore; a plurality of radially spaced arms adapted to mount cutting tools adjacent one end of the arms for engaging a portion of the hole to be enlarged and disposed exteriorly of the bore, means for mounting the arms for free movement parallel to an axis of the bore over a predetermined distance, and pivotable about axes transverse to the axis of the bore adjacent another end of the arms proximate to the piston, means on the arms for engaging the skirt portion when the piston moves towards the open end of the bore for pivoting the ends of the arms outwardly relative to the axis of the bore in opposition to a pivotal force from the weight of the arms and for biasing the skirt and the piston axially away from the open end of the bore when the cutting tools are disengaged from a portion of the subsurface hole; and stop means for limiting the outward pivotal movement of the arms.

Claim 3

Apparatus according to claim 1 including a member secured to the tool body and projecting through an axial center bore in the piston to a region in fluid communication with the exterior of the body, a fluid passage in the end of the member projecting through the piston; the member having a sufficient length that the bore in the tool body fluidly communicates with the exterior of the body when the arms are fully pivoted outwardly.

Claim 4

Apparatus according to claim 1 wherein the tool body includes a flange adjacent each side of each arm, each pair of flanges adjacent each arm having aligned slots engaging shaft means secured to each arm such that the arms are pivotal about axes of said shaft means and are movable in a direction parallel to the axis of the bore within the confines of the slot.

Claim 5

Apparatus according to claim 3 including at least two pluralities of arms, ends of each plurality of arms projecting outwardly from the axis of the hole a distance different from the other pluralities of arms when the arms are fully pivoted outwardly.

Claim 6

Apparatus for enlarging the diameter of subsurface holes comprising: a tool body adapted to be secured to a drill string and including hydraulic actuating means having an axially extending skirt portion; a plurality of radially arranged arms disposed adjacent the skirt portion and adapted to mount cutting tools adjacent an end of the arms remote from the actuating means; means for mounting the arms for pivotal movement about axes substantially transverse to an axis of the skirt portion, and for movement parallel to the axis of the skirt portion over a predetermined distance; a first skirt engaging surface on each arm for positioning the end of the arm adjacent the axis of the skirt portion; a second surface on each arm for engaging a free end of the skirt portion and pivoting the end of the arm in a direction away from the axis of the tool body in response to actuation of the actuating means; a third skirt engaging portion for positioning the ends of the arms remote from said axis; the predetermined distance being sufficient that the second skirt engaging portion is disposed adjacent the free end of the skirt portion after the hydraulic means have been actuated and the arms are at one end of their axial movement; means for securing the arms to the tool body such that they are pivotable and axially movable over the predetermined distance; stop means for limiting the pivotal movement of the arms in a direction away from the axis of the skirt portion; and means for limiting the axial movement of the skirt portion in response to actuation of the actuating means.

Claim 7

Apparatus for enlarging the diameter of subsurface holes comprising: a tool body adapted to be secured to a drill string and including hydraulic actuating means having an axially extending skirt portion; a plurality of radially arranged arms disposed adjacent the skirt portion and adapted to mount cutting tools adjacent an end of the arms remote from the actuating means; means for mounting the arms for pivotal movement about axes substantially transverse to an axis of the skirt portion, and for movement parallel to the axis of the skirt portion over a predetermined distance; a first skirt engaging surface on each arm for positioning the end of the arm adjacent the axis of the skirt portion; a second surface on each arm for engaging a free end of the skirt portion and pivoting the end of the arm in a direction away from the axis of the tool body in response to actuation of the actuating means; a third skirt engaging portion for positioning the ends of the arms remote from said axis; the predetermined distance being sufficient that the second skirt engaging portion is disposed adjacent the free end of the skirt portion after the hydraulic means have been actuated and the arms are at one end of their axial movement; means for securing the arms to the tool body such that they are pivotable and axially movable over the predetermined distance; stop means for limiting the pivotal movement of the arms in a direction away from the axis of the skirt portion; and means for limiting the axial movement of the skirt portion in response to actuation of the actuating means.

Claim 8

Apparatus according to claim 5 wherein the means for mounting the arms includes laterally spaced flanges secured to the tool body adjacent sides of the arms and shafts connected with the flanges.

Claim 9

Apparatus according to claim 6 wherein the body defines a cylinder and the actuating means include a piston disposed in the cylinder and secured to the skirt portion, the cylinder being in flow communication with a fluid carrying portion of the drill string and provided with an opening adjacent the piston to fluidly communicate an interior space of the cylinder with the exterior of the tool body when the free end of the skirt portion is adjacent the third engaging surface and the arms moved axially over the predetermined distance in a direction opposite to a direction the piston moves when pressure is applied to the interior space.

Claim 10

Apparatus for enlarging the diameter of sub-surface holes, the apparatus comprising: a. a tool body having: i. an end flange adapted to secure one end of the tool body to a drill string; ii. a cylinder having an axis, the cylinder being adapted to be in fluid communication with a fluid carrying portion of the drill string and having one end secured to the flange and another end open; and iii. a plurality of pairs of laterally spaced elongated flanges adjacent a periphery of the cylinder extending axially away from the end flange; b. an axially movable piston disposed in the cylinder and including a skirt portion projecting past the open end; c. an arm disposed intermediate a pair of flanges having a free end adapted to mount a cutting tool and another end adjacent the open end of the cylinder pivotally and axially movably secured to the flanges, the axial movement being limited to a predetermined amount, the arms having a first, second and third skirt-engaging portion progressively engageable by the skirt portion when the piston moves away from the end flange in response to a fluid pressure being applied to the cylinder such that the arm is pivoted outwardly in response to such movements of the skirt portion while a free end of the skirt portion is in engagement with the second surface; d. means for relieving the pressure in the cylinder in response to a free end of the skirt portion being positioned adjacent the third engaging surface of the arm and the arm is axially farthest removed fRom the end flange; e. stop means for limiting the pivotal movement of the arm in a direction away from an axis of the cylinder; f. means for pivotally and axially movably securing the other end of the arm to the flanges; and g. means connected with ends of the flanges remote from the end flange for connecting another end of the tool body to a drill string.

Claim 11

Apparatus for enlarging the diameter of sub-surface holes, the apparatus comprising: a. a tool body having: i. an end flange adapted to secure one end of the tool body to a drill string; ii. a cylinder having an axis, the cylinder being adapted to be in fluid communication with a fluid carrying portion of the drill string and having one end secured to the flange and another end open; and iii. a plurality of pairs of laterally spaced elongated flanges adjacent a periphery of the cylinder extending axially away from the end flange; b. an axially movable piston disposed in the cylinder and including a skirt portion projecting past the open end; c. an arm disposed intermediate a pair of flanges having a free end adapted to mount a cutting tool and another end adjacent the open end of the cylinder pivotally and axially movably secured to the flanges, the axial movement being limited to a predetermined amount, the arms having a first, second and third skirt-engaging portion progressively engageable by the skirt portion when the piston moves away from the end flange in response to a fluid pressure being applied to the cylinder such that the arm is pivoted outwardly in response to such movements of the skirt portion while a free end of the skirt portion is in engagement with the second surface; d. means for relieving the pressure in the cylinder in response to a free end of the skirt portion being positioned adjacent the third engaging surface of the arm and the arm is axially farthest removed fRom the end flange; e. stop means for limiting the pivotal movement of the arm in a direction away from an axis of the cylinder; f. means for pivotally and axially movably securing the other end of the arm to the flanges; and g. means connected with ends of the flanges remote from the end flange for connecting another end of the tool body to a drill string.

Claim 12

Apparatus according to claim 8 wherein the means for securing comprises a shaft disposed intermediate each pair of flanges and the arm disposed between such flanges, and a slot in each flange, the shaft being axially movable in the slot to pivotally and axially movably secure the arm to the pair of flanges.