Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS1750629 A
Publication typeGrant
Publication dateMar 18, 1930
Filing dateOct 15, 1928
Priority dateOct 15, 1928
Publication numberUS 1750629 A, US 1750629A, US-A-1750629, US1750629 A, US1750629A
InventorsCrum Roland R
Original AssigneeH C Smith Mfg Company
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Expansible underreamer
US 1750629 A
Abstract  available in
Images(3)
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

March 18, 1930. R. R. CRUM EXPANSIBLE UNDERREAIBR 3 Sheets-Sheet .l

A TTORNEYJ March 18, 1930. R, R, CRQM 1,750,629

EXPANSIBLE UNDERREAMER Filed Oct. 15, 1926 a Shoots-Sheet 2 INVENTOR. /f0lana I? Cram;

BY fiwzzwiwa A TTORNEYJ Patented Mar. 18, 1930 UNITED STATES PATENT OFFICE ROLAND R. CRUM, OF WHITTIER, CALIFORNIA, ASSIGNOR T0 H. C. SMITH MANUFAC- TURING COMPANY, OF WHITTIER, CALIFORNIA, A CORPORATION OF CALIFORNIA EXPANSIBLE UNDERREAMER Application filed. October 15, 1928. Serial No. 312,476.

This invention relates to an expansible underreamer having at its periphery cutters movable laterally to and from the drilling axis of the underreamer for expansion and collapsion of the cutters. The present invention appertains particularly to means for holding the cutters in retracted or collapsed position and operable to lock the cutters 1n expanded plates the provision of cutters longitudinally movable to eflect expansion and collapsion by means of guides, latches to retain said cutters in collapsed position and movable to maintain the cutters in expanded position.

It is an object of this invention to pro vide a novel guide and latch mechanism which may be manipulated from the outside of the underreamer, and which will be out of the way both in expanded working position and collapsed position.

These objects together with other ob ects and corresponding accomplishments as will be ascertained from the appended specification are obtained by means of the embodiment of my invention illustrated in the accompanying drawing in which 0 Fig. 1 is a central longitudinal section through an underreamer in collapsed pos1- tion and within a well casing, a fragment of a well casing and shoe being shown; Fig. 2 is a central longitudinal section with the underreamer parts in initial expanding pos1- tion and going out of the casing; Fig. 3 is a central longitudinal view showing the underrcamer in final expanded position out of the casing: Fig.4 is an elevation of the underreamer collapsed and partly within a casing, the latter being broken out to better show the underreamer: Figs. 5. 6 and 7 are sections as seen on the planes correspondingly indicated in Fig. 3; Fig. 8 is a perspective view of a guide or expander: Fig. 9 is a perspective view of a catch; Fig. 10 is an elevation of the lower impeller block; and Fig. 11 is an end view of the block shown in Fig. 10.

The embodiment of the invention shown herein includes three cutters and associated parts. However, more or less cutters may be used, and as each cutter and its cooperating position. The invention contem-- parts are of like construction, it will be only necessary to describe one.

A body 15 has at its upper end a threaded pin 16 for attachment of the underreamer to a drill string and a threaded socket 17 at the bottom for attachment of the usual drill tools. Extending centrally through the body from the pin end is a circulation passage 18 ending at a cutter chamber 19. Extending through the cutter chamber and communicating with passage 18 is a wash pipe 20 which opens to the socket. Suitable passages open from the circulation passage to direct the flow of wash to the cutter chamber. Longitudinally extending cutter openings are provided in the body at the chamber 19 and are marked with the reference numeral 21. Above the openings 21 are pockets 22 having outer walls with openings 23 for accommodation of latch shoes. Disposed within each pocket and on the inner'wall thereof is an offset or a rider plate 24 having a bevelled lower face. This plate forms an offset step. It will be noted that the bod is formed of separable sections to provi e for convenience in assembly and in manu' facture. i

Slidably mounted upon the wash pipe 20 and within the chamber 19 is a cross head impeller 25. The cross head is provided with a spring socket 26 and at the upper portion has a triangular end 27 from which extend wings 28. Each wing has a bdre 29. Mounted Within the socket is a compression spring 30 tending to move the impeller cross head upwardly. Fulcrumed to the body by means of pins 32 are shaft blocks 31'. The shaft blocks have recesses so that they straddle the wings, and it will be noted that the pins 32 are of less diameter than the holes 29 to provide a limited lateral movement of the shaft blocks.

in each pocket 22 is an expansing guide block.

39, best shown in Fig. 8. The guide block has a sloping front face 40 and a rear channel 41 adapted to receive the finger 36. The guide block is of bident form having a sloping surface 42 at its crotch. Mounted in each pocket 22 is a rider key or latch 43 having a rear face with a stepped portion 44. A shoe 45 is attached to the latch and extends through the opening 23. Slidably mounted in each pocket above and in engagement with the shoe and latch therein is a spring follower 46. Disposed within each follower is a compression spring 47 tending to move the follower and latch downwardly.

In the drawings, a casing A is shown with a shoe at the lowerend thereof. The underreamer is collapsed with the parts in position shown in Fig. 1. In this position the cutter structures are in lower longitudinal position with the main spring 30 collapsed and the upper ends of the cutter members disposed in inner position. The fingers 36 are" disposed between the legs of the guide blocks 39 and at the rear in registration with the rear channels. The latches 43 are disposed in the channels 41 fingers 36 resting thereagainst, the lower ends of the latches resting in the notches at the tips of the fingers. The follower sprin s 4'? are fully expanded holding the latches 43 in lower position. It will be noted that the shoes 45 are in innermost position. With the underreamer parts in this condition, the tool is inserted in the casing, the shoes 45 bearing against the casing and thereby maintaining the cutters in collapsed position. As the underreamer moves out of the casing, as shown in Fig. 2, the lateral pressure upon the shoes 45 is relieved, and they are free to be moved outwardly. They are caused to be moved upwardly and outwardly by reason of the pressure of main springs 30 which acts upon the cutters moving them together with the fingers 36 and the latches 43 upwardly against the action of springs 47, which are of less strength than the spring 30. However, the upward movement of the sloping ends of fingers 36 bearing upon the coacting crotch sloping surfaces, cause the fingers to be directed outwardly and out of registration with the latches 43. This initial opening position causes the shoes 45 to be disposed in their outermost position. The fingers next ride upwardly against the outer face of the guide blocks to the position shown in Fig. 3, and the springs 47 cause the latches 43 to be moved downwardly and inwardly. The rear faces of the latches in their lower position are disposed below the step plate 24, with their bevelled inner corners resting against the sloping lower edges of the plates. In their upper position as shown in Fig. 2, the latches 43 overlap the plate 24 and the latter are in its outer position.

What I claim is 1. In an underreamer, the combination of a body having a longitudinally extending cavity in its periphery with a pocket at the upper end, said pocket having an outer wall, a cutter accommodated in said cavity for longitudinal play therein and having a connection to said body so that it may be moved laterally into and out of expanded position, means tending to move said cutter to its upper longitudinal position, a catch secured to the upper end of said cutter having a bearing surface, said catch having its tip within said pocket, a guide in said pocket having a coacting surface for sliding engagement by said bearing surface, one of said surfaces sloping to direct said catch outwardly against the outer wall of said pocket on its upward movement and dispose said cutter in expanded position and inwardly to the rear of said guide ondownward movement with said cutter in collapsed position, a longitudinally shiftable latch movable in said pocket to engage and retain said catch at its lower position, and means urging said latch into lower position with said bearing surface out of engagement with said coacting surface.

2. In an underreamer, the combination of a body having a longitudinally extending cavity in its periphery with a pocket at the upper end, said pocket having an outer wall, a cutter accommodated in said cavity for longitudinal play therein and having a connection to said body so that it may be moved laterally into and out of expanded position, means tending to move said cutter to its upper longitudinal position, a catch secured to the upper end of said cutter having a sloping bearing surface, said catch having its tip within said pocket, a guide in said pocket having a coacting surface for sliding engage ment by said bearing surface so as to direct said catch outwardly against the outer wall of said pocket on its upward movement and dispose said cutter in expanded position and inwardly to the rear of said guide on downward movement with said cutter in collapsed position, a longitudinally shiftable latch mov able in said pocket to engage and retain said catch at its lower position, and means urging said latch into lower position with its hearing surface out of engagement with said coacting surface.

3. In an underreamer, the combination of a body having a longitudinally extending cavity in its periphery with a pocket at the upper end, said pocket having an outer wall, a cutter accommodated in said cavity for longitudinal play therein and having a connection to said body so that it may be moved laterally into and out of expanded position. means tending to move said cutter to its upper longitudinal position, a catch secured to the upper end of said cutter having a hearing surface, said catch having its tip within said pocket, a guide in'said pocket having a coacting sloping surface for sliding engagement by said bearing surface so as to direct said catch outwardly against the outer wall of said pocket on upward movement and dispose said cutter in expanded position and inwardly to the rear of said guide on downward movement with said cutter in collapsed position, a longitudinally shiftable latch movable in said pocket to engage and retain said catch at its lower position, and means urging said latch into lower position with said bearing surface out of engagement with said coacting surface.

4. In an underreamer, the combination of a body having a longitudinally extending cavity in its periphery with a pocket at the upper end, said pocket having an outer wall, a cutter accommodated in said cavity for longitudinal play therein and having a connection to said body so that it may be moved laterally into and out of expanded position, means tending to move said cutter to its upper longitudinal position, a catch secured to the upper end of said cutter having a hearing surface, said catch having its tip within said pocket, a guide in said pocket having a coacting surface for sliding engagement by said bearing surface, one of said surfaces sloping to direct said catch outwardly against the outer wall of said pocket on upward movement and dispose said cutter in expanded position and inwardly to the rear of sair guide on downward movement with said cutter in collapsed position, a longitudinally shiftable latch movable in said pocket to engage and retain said catch atits lower position, said latch having a bevelled inner upper edge, a ramp on said body in registration with said latch to provide a complementary shoulder to direct said latch outwardly, and means urging said latch into lower position with said bearing surface out of engagement with said coacting surface.

5. In an underreamer, the combination of a body having a longitudinally extending cavity in its periphery with a pocket at the upper end, said pocket having an outer wall, a cutter accommodated in said cavity for longitudinal play therein and having a connection to said body so that it may be moved laterally into and out of expanded position, means tending to move said cutter to its upper longitudinal position, a catch secured to the upper end of said cutter having a sloping bearing surface, said catch having its tip within said pocket, a guide in said pocket having a coacting surface for sliding engagement by said bearing surface so as to direct said catch outwardly against the outer wall of said pocket on upward movement and dispose said cutter in expanded posltion and inwardlyto the rear of said gu de on downward movement with said cutter n collapsed position, a longitudinally shdable a coacting surface for latch movable in said pocket to engage and retain said catch at its lower position, said latch having a bevelled inner upper edge, a ramp on said body in registration with said latch to provide a complementary shoulder for the bevelled edge of said latch to direct said latchoutwardly, and means urging said latch into lower position with said bearing surface out of engagement with said coactin g surface.

6. In an underreamer, the'combination of a body having a longitudinally extending cavity in its periphery with 'a pocket at the upper end, said pocket having an outer wall,

a cutter accommodated in said cavity for longitudinal play therein and having a connection to said body so that it may be moved laterally into and out of expanded position, means tending to move said cutter to its upper longitudinal position, a catch secured to the upper end of said body having a hearing surface, said catch having its tip within said pocket, a guide in said pocket having a sloping coacting surface for engagement by said bearing surface to direct said catch outwardly against the outer wall of said pocket on upward movement and dispose said cutter in expanded position and inwardly to the rear of said guide on downward movement with said cutter in collapsed position, a longitudinally shiftable latch movable in said pocket to engage and retain said catch at its lower position, said latch having a bevelled inner upper edge, a ramp on said body in registration with said latch to provide a complementary shoulder for the bev elled edge of said latch to direct said latch outwardly, and means urging said latch into lower position with said earing surface out of engagement with said coacting surface.

7. In an underreamer,the combination of a body having a longitudinally extending cavity in its periphery with a pocket at the upper end, said pocket having an outer wall, a cutter accommodated in said cavity for longitudinal playitherein and having a connection to said body so that it may be moved laterally into and out of expanded position, means tending to move said cutter to its upper longitudinal position, a catch secured to the upper end of said cutter having a bearing surface,,said catch having its tip within said pocket, a guide in said pocket having sliding engagement by said bearing surface, one of said surfaces sloping to direct said catch outwardly against the outer wall of said pocket on upward movement of said finger and dispose said cutter in expanded position and inwardly to the rear of said guide on downward movement with said cutter in collapsed position, a longitudinally shiftable latch movable in said pocket to engage said catch at its lower position, said latch having a bevelled inner upper edge, and an inset lateral rear surface at its upper end a ramp on said body in registration with said latch to provide a complementary shoulder for the bevelled edge of said latch and an offset bearing surface for said inset surface whereby in the upper position of said latch said inset surface will bear against said offset-surface and in the lower position of said latch said bevelled edge will bear against said ramp, and means urging said latchv into lower position with said bearing surface out of engagement with said coacting surface.

8. In an underreamer, the combination of a body having a longitudinally extending cavity in its periphery with a pocket at the upper end, said pockethaving an outer wall, a cutter accommodated in said cavity for longitudinal play therein and having connection to said body so that it may be moved lateral-- ly into and out of expanded position, means tendin to move said cutter to its upper longitudinaIposition, a catch secured to the upper end of said cutter having a sloping bearing surface, said catch having its tip Within said pocket, a guide in said pocket having a coacting surface for sliding engagement by said bearing surface so as to direct said catch outwardly against the outer wall of said pocket on upward movement of said catchand dispose said cutter in expanded osition and inwardly to the rear of said gui e on downward movement of said catch with said cutter in collapsed position, a longitudinally shiftable latch movable in said pocket to engage and retain said catch at its lower position, said latch having a bevelled inner upper edge and an inset lateral rear surface at its upper end, a ramp on said body in registration with said latch to provide a complementary shoulder for the bevelled edge of said latch and an offset bearing surface for said inset surface whereby in the upper position of said latch said inset surface will bear against said offset surface and in the lower position of said latch said bevelled edge will bear against said ramp, and means urging said'la'tch into lower position with said bearing surface out of engagement with said coacting surface.

9. In an underreamer, the combination of a body having a longitudinally extending cavity in its periphery with a pocket at the upper end, said pocket having an outer wall, a cutter accommodated in said cavity for longitudinal play therein and having a connection to said body so that it may be moved laterally into and out of expanded position, means tending to move said cutter to its upper longitudinal position, a catch secured to the upper end of said cutter having a bearing surface. said catch having its tip within said pocket, a guide in said pocket having a sloping coacting surface for engagement by said bearing surface to direct said catch outwardly against the outer wall of said pocket on upward movement of said catch and dispose said cutter in expanded position and inwardly to the rear of said guide on downward movement with saidcutter in collapsed position, a longitudinally shiftable latch movable in said pocket to en gage and retain said catch at its lower position, said latch having a. bevelled inner upper edge and an inset lateral rear surface at its upper end, a ramp on said body in registration with said latch to provide a complementary shoulder for the bevelled edge of said latch and an offset bearing surface for said inset surface whereby in the upper position of said latch said inset surface will bear against said offset surface and in the lower position of said latch said bevelled ed e will bear against said ramp, and means urging said latch into lower position with said bearing surface out of engagement with said coacting surface.

10. In an underreamer, the combination of a body having a longitudinally extending cavity in its periphery with a pocket at the upper end, said pocket having an outer wall, a cutter accommodated in said cavity for longitudinal play therein and having a connection to said body so that it may be moved laterally into and out of expanded position, means tending to move said cutter to its upper longitudinal position, a catch secured to the upper end of said cutter having a bearing surface, said catch having its tip within said pocket, a bident guide in said pocket straddling said finger and having a coacting surface at its crotch for sliding engagement by said bearing surface, one of said surfaces sloping to direct said catch outwardly against the outer wall of said pocket 011 upward movement and dispose said cutter in expanded position and inwardly to the rear of said guide on downward movement with said cutter in collapsed position, a longitudinally shiftable latch movable in said pocket to engage and retain said catch at its lower position. and means urging said latch into lower position with said bearing surface out of engagement with said coacting surface.

11. In an underreamer, the combination of a body having a longitudinally extending cavity in its periphery with a pocket at the upper end, said pocket having an outer wall, a cutter accommodated in said cavity for longitudinalplay therein and having connection to said body so that it may be moved laterally into and out of expanded position, means tending to move said cutter to its upper longitudinal position, a catch secured to'the upper end of said cutter having a bearing surface, said catch having its tip within said pocket, a bident guide in said pocket straddling said catch and having a coacting surface at its crotch for sliding engagement by said bearing surface, one of said surfaces sloping to direct said catch outwardly against the outer wall of said pocket on upward movement and dispose said cutter in expanded position and inwardly to the rear of said guide on downward movement with said cutter in collapsed position, a lon itudinally shiftable latch movable in said pocket to engage and retain said catch at its lower position, said latch having a bevelled inner upper edge, a ramp on said body in registration with said latch to pfovide a complementary shoulder for the bevelled'edge of said latch to direct said latch outwardly, and means urging said latch into lower position with said bearing surface out of engagement with said coacting surface;

' 12. In an underreamer, the combination of a body having a longitudinally extending cavity in its periphery with a pocket at the upper end, said pocket having an outer wall, a cutter accommodated in said cavity for longitudinal play therein and having a connection to said body so that it may be moved laterally into and out of expanded position,

' means tending to move said cutter to its upper longitudinalposition, a catch secured to the upper end of said cutter having a bearing surface, said catch having its tip within said pocket, a bident guide in said pocket straddling said catch and having a coacting surface at itscro-tch for sliding engagement by said bearing surface, one of said surfaces sloping to direct said catch outwardly against the outer wall of said pocket on upward movement and dispose said cutter in expanded position and inwardly to the rear of said guide on downward movement with said cutter in collapsed position, a longitudinally shiftable latch movable in said pocket to engage and retain sai catch at its lower position, said latch having a bevelled inner upper edge, a ramp on said body in registration with said latch to provide a complementary shoulder for the bevelled edge of said latch to direct said latch outwardly, and means urging said latch into lower position with said bearing surface out of engagement with said coacting surface,

13. In an underreamer, the combination of a body having a longitudinally extending cavity in its periphery with a pocket at the upper end, said pocket having an outer wall, a cutter accommodated in said cavity for longitudinal play therein and having a connection to said bod so that it maybe moved laterally into an out of expanded position, means tending to move said cutter to its upper longitudinal position, a catch secured to the upper end of said cutter and having a sloping bearing surface, said catch having its tip within said pocket, a bident guide in said pocket straddling said catch and having a coacting surface for sliding engagement by said bearing surface so as to direct said catch outwardly against the outer wall of said pocket on upward movement of said finger and dispose said cutter in expanded position and inwardly to the rear of said guide on downward movement with said cutter in collapsed position, a longitudinally shiftable latch movable in said pocket to engagesaid catch at its lower position, said latch having a bevelled inner upper edge, a ramp on said body in registration with said latch to provide a complementary shoulder for said bevelled edge to direct said latch outwardly,

and means urging said latch into lower position with said bearing surface out of engagewithin said pocket, a bident guide in said pocket straddling said catch and having a coacting surface for sliding engagement b said bearing surface so as to direct said cuts outwardly against the outer wall of said pocket on upward movementof said finger and dispose said cutter in' expanded position and inwardly tothe rear of said guide on downward movement with said cutter in collapsed position, a longitudinally shiftable latch movable in said pocket to engage and retain said catch at its lower position, said latch having a bevelled inner upper edge, a ramp on said body in registration "with said latch to provide a complementary shoulder for said bevelled edge to direct said latch, outwardly, and means urging said latch into lower position with said caring surface out of engagement with said coacting surface.

15. In an underreamer, the combination of a body having a longitudinally extending cavity in its periphery with a pocket at the upper end, said pocket having an outer wall, a cutter accommodated in said cavity for lon gitudinal play therein and having a connection to said body so that it may be moved laterally into and out of expanded position, means tending to move said cutter to its upper longitudinal position, a catch secured to the upper end of said cutter and having an osition, and means urging said latch into ower position with said bearing surface out of engagement with said coacting surface.

16. In an underreamer, the combination of a body having a longitudinally extending .cavity in its periphery with a pocket at the upper end, said pocket having an outer wall, a cutter accommodated in said cavity for longitudinal play therein and having a connectioh to said body so that it may be moved laterally into and out of expanded position, means tending to move said cutter to its upper longitudinal position, a catch secured to the upper end of said cutter having an upwardly directed finger with a bearing surface, said finger having its end within said pocket, a bident guide in said pocket straddling said finger and having a sloping coacting surface at its crotch for engagement by said bearing surface to direct said finger outwardly against the outer wall of said pocket on upward movement and dispose said cutter 1n expanded position and inwardly to the rear of said guide on downward movement with said cutter in collapsed position, a longitudinally slidable latch movable in said pocket to engage and retain said catch at its lower position, and means urging said latch to its lower position with said bearing surface out of engagement with said coacting surface.

17. In an underreamer, the combination of a body having a longitudinally extending cavity in its periphery with'a pocket at the upper end, said pocket having an outer wall, a cutter accommodated in said cavity for longitudinal play therein and having a connection to said body so that it may be moved laterally into and out of expanded position, means tending to move said cutter to its up per longitudinal position, a catch secured to the upper end of said cutter having an upwardly directed finger with a bearing surface, said finger having its end within said pocket, a bident guide in said pocket straddling said finger and havin a sloping coacting surface at its crotch for. engagement by said bearing surface to direct said finger outwardly against the outer wall of said pocket on upward movement and dispose said cutter in expanded position and inwardly to the rear of said guide on downward movement with said cutter in collapsed position, a longitudinally slidable latch movable in said pocket to engage and retain said finger at its lower position, said latch having a bevelled inner upper edge, a ram on said body in re istration with said latcii to provide a complementary shoulder for the bevelled edge of said latch to direct the latter outwardly and means urging said latch into lower position with said bearing surface out of the engagement with said coacting surface.

, 18. In an uiiderreamer, the combination of a body having a longitudinally extending cavity in its periphery with a pocket at the upper end, said pocket having an outer wall, a cutter accommodated in said cavity for longitudinal play therein and having a connection to said body so that it may be moved laterally into and out of expanded position, means tending to move said cutter to its upper longitudinal position, a catch secured to the upper end of said cutter and having an upwardly directed finger with a bearing surface, said finger having its end within said pocket, a bident guide in said pocket straddling said finger and having a sloping coacting surface at its crotch for engagement by said bearing surface to direct said finger outwardly against the outer wall of saidpocket on upward movement of said finger and dispose said cutter in expanded position and inwardly to the rear of said guide on downward movement of said finger with said cutter in collapsed position, alongitudinally slidable latch movable in said pocket to engage and retain said finger at its lower position, said latch having a bevelled inner upper edge and an inset lateral rear surface at its upper end, a ramp on said body in registration with said latch to provide a complementary shoulder for the bevelled edge of said latch and an offset bearing surface for said inset surface whereby in the upper position of said latch said inset surface will be against said offset 9 surface and in the lower position of said latch said bevelled edge will bear against said ramp, and means urging said latch into lower position with said bearlng surface out of the engagement with said coacting surface.

' 19. In an underreamer, the combination of a body having a longitudinally extending cavity in its periphery with a pocket at the upper end, said pocket having an outer wall, a cutter accommodated in said cavity for longitudinal play therein and having a fulcrum connection to said body at its lower end so that it may be swung laterally into and out of expanded position, means tending to move said cutter to its upper longitudinal position, a catch secured to the upper end of said cutter and having an upwardly directed finger with a bearing surface, said finger having its end within said pocket, a guide loosely mounted in said pocket and having a coacting surface for sliding engagement by said bearing surface, one of said surfaces sloping to direct said finger outwardly against the outer wall of said pocket on upward movement and dispose said cutter in expanded position and inwardly to the rear of said guide on downward movement of said finger with said cutter in collapsed position, a longitudinally slidable latch movable in said pocket to engage the tip of and retain said finger at its upper position, and resilient means urging said latch into lower position with said bearing surface out of engagement with said coactin surface.

20. In an un erreamer, the combination of a body having a longitudinally extending cavity in its periphery with a pocket at the upper end, said pocket having an outer wall, a cutter accommodated in said cavity for longitudinal play therein and having a fulcrum connection to said body at its lower end so that it may be swung laterally into and out of expanded position, means tending to move said cutter to its upper longitudinal position, a catch secured to the upper end of said cutter and having an upwardly directed finger with a bearing surface, said finger having its end Within said pocket, abident guide loosely mounted in said pocket straddling said finger and having a coacting surface at its crotch for sliding engagement by said bearing surface, one of said surfaces sloping to direct said finger outwardly against the outer wall of said pocket on upward movement and dispose said cutter in expanded position and inwardly to the rear of said guide on downward movement with said cutter in collapsed position, a longitudinally slidable latch movable in said pocket to en- 4 gage the tip of and retain said, finger at its lower position, and resilient means urging said latch into lower position With said bearing surface out of engagement with said coacting surface.

In witness that I claim the foregoing I have hereunto subscribed my name this 20th day of September, 1928.

ROLAND R, CRUM,

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US7387175 *Dec 22, 2004Jun 17, 2008Zeer Robert LWindow reaming and coring apparatus and method of use
US7401666 *Jun 8, 2005Jul 22, 2008Security Dbs Nv/SaReaming and stabilization tool and method for its use in a borehole
US7584811Jun 25, 2008Sep 8, 2009Security Dbs Nv/SaReaming and stabilization tool and method for its use in a borehole
US7658241Apr 19, 2005Feb 9, 2010Security Dbs Nv/SaUnderreaming and stabilizing tool and method for its use
US7975783Aug 28, 2009Jul 12, 2011Halliburton Energy Services, Inc.Reaming and stabilization tool and method for its use in a borehole
Classifications
U.S. Classification175/278, 175/346, 175/283, 175/285
International ClassificationE21B10/26, E21B10/34
Cooperative ClassificationE21B10/34
European ClassificationE21B10/34