US2450223A

US2450223A - Well reaming apparatus

Info

Publication number: US2450223A
Application number: US565121A
Authority: US
Inventors: William R Barbour
Original assignee: Individual
Current assignee: Individual
Priority date: 1944-11-25
Filing date: 1944-11-25
Publication date: 1948-09-28
Anticipated expiration: 1965-09-28

Description

W. R. BARBOUR' WELL REAMING APPARATUS Sept. 28, 194

3 Sheets-S 1 F led Nov. 25, 1944 em 8 W. m5.%m A u n m M W a. T fl W4 M R T a f MYM .J 4 M B Y A L A v. M \\N k.um \A 1 a a A w umH. .w. w wmm w A, S T f. T. 1 3 J w k w Z Sept. 28, 1948.

w. R. BARBOUR WELL REAMING APPARATUS Filed Nov. 25, 1944 If; E- S 3 Sheets-Sheet 3 xca l 1:]

Tail 5 Patented Sept. 2a, 1948 WELL ammo arraaa'rus William B. Barbour, Atlanta, Ga.

Application November 2;, 1044, Serial No. 508,121

r 13 Claims.

--Generically this invention relates to reaming devices, but it more particularly is directed to a rotary device or apparatus for reaming out to a larger diameter any desired portion of oil wells and the like. Oneof the principal objects of this invention is the. provision of a device of this character attachable to a string of'drill pipe, controllable from the surface of the ground, and comprising an improved hollow reamer shaft, and expansible reamer arm construction and shoe assembly associated with said shaft operable to effect reaming out of a chamber or enlarging any portion of the well bore and permitting a fluid circulation through the device including the shoe to the bottom of the well for clean out purposes and cooling of the reamer arms.

Another object of this invention is the provision of an upper collar structure having detachable connection with the end of the drill pipe and adapted to be slidably mounted on the upper end of the reamer shaft and to impart rotary motion thereto and to the attached reamer arms and thrust rods. i

A further important object of this invention is the provision of a reamer arm assembly adapted to be mounted on streamer shaft, and comprising a plurality of articulated sets of reamer arms attached at one end to an upper or control collar .and at the other end to a lower slidable collar and movable into overlying parallelism with the reamer shaft and to expanded or reaming position, and means associated with' said collars adapted to transmit-force and. downward movement from the upper to the lower collar and arms when expanded or moving in reaming direction, said arms being automatically foldable by the upward movement of said upper collar.

Another important object of this invention is the provision of a hollow reamer shaft adapted of a drill pipe and having means adapted to prevent its dropping out of or. becoming detached from said collar, a plurality of sets of e p nsible reamer arms associated with ,said shaft with their upper ends attached to said collar andtheir lower ends attached to a lower slidable collar mounted on said shaft; means in connection with said shaft fol-preventing the lower collar from slid-q ing down said reamer shaft until the reamer arms have substantially reached their expanded posit-ion, and means in connection with said shaft to permit the folding of the reamer arms into-overlying parallelism therewith at any desired point throughout its length.

A further important object of this invention is .th'e'prov-ision of an articulated reamer arm structure mounted on a reamer shaft and adapted to v be inserted in a drilled well in folded parallelism with the shaft, and means in connection with said shaft and coacting with said arm structure to initially start the outward movement of said arms in expanding direction.

A still further important object of this invenand the formation of the foot structure adapted to prevent movement and sinking of the 'base,

thereby insuring the flow of the circulating fluid through the shoe to the bottom of the well.

With these and other obiects in view, which will become apparent as the description proceeds,

the invention resides in the construction, combination and arrangement of parts, hereinafter .more fully described and claimed, in which like I .to be slidable through a collar attached to the end 7 characters of reference indicate like parts throughout the severalflgures, of which: Fig. l is a view in elevation with the reamer arms in closed position.

Fig. 2 is an elevation similar to Fig. 1 with the arms in expanded position.

Fig. 3 is a sectional view with the arms clos and in elevation.

Fig. 4 is a view similar to Fig. 3 with the arms expanded and in fragmentary elevation.

Fig. 5 is a fragmentary sectional view showing the ball and cams in arm opening position.

Fig. 6 is a fragmentary sectional view showing the lower arm cams in the cam receiving recesses. Fig. '7 is a cross section on the line 1-1 of Fig. 3 showing the cam retaining pins in elevation.

Fig. 8 shows ,the upper collar partly in section, a portion of the connected drill pipe in section and connected parts in elevation.

Fig. 9 is a similar view to Fig. 8 in elevation with the upper collar partly in section.

Fig. 10is a fragmentary longitudinal sectional view with the upper reamer arms in elevation.

Fig. 11 is a cross section on the line ll-li of Fig. 10. V

Fig. 12 is'a cross section on the line lI-l! of Fig. 8.

Fig. 13 is a cross section on the line it-iiof Fig. 14 is a longitudinal section of the shoe structure and portion of the reamer shaft.

Fig. 15 is a cross section On the line ll-ll of Fig. 14.

Fig. 16 is a sectional view of a portion of an oil well showing the reaming device in operative position therein.

Fig. 17 is an elevation of a modified form of reamer arm construction.

The devices of this character with which I am familiar have proven deficient in presenting complex structures, expensive to produce, diflicult to readily position at any desired level, and in other ways unsatisfactory, and it was to overcome such disadvantages by providing a flexible device comprising an upper collar attachable to a string of drill pipe adapted to carry and control the articulated reamer arms, and to impart rotary motion to the hollow reamer shaft slidably connected therewith, said shaft carrying a fluid and ball controlled cam mechanism adapted to initially start the expanding movement of the reamer arms, a slidable lower collar on said shaft connected to the ends of-the lower reamer arms, means carried by said shaft coacting with the cam means carried by the lower ends of said lower arms to hold the lower collar against downward movement until said arms have substantially reached their limit of expansion, and a compound shoe structure adapted to rest on the bottom of the well and to support said rotatable shaft and reaming assembly, said shoe including a supporting thrust bearing and axial bearing surface for said shaft and means for directing the fluid flow from said shaft therethrough to the bottom of the well, that I designed the device forming the subject matter of this invention.

In the illustrated embodiment characterizing this invention there is shown a drill pipe I, externally threaded at its lower end as at 2, and an upper collar 3 formed with a threaded countersunk opening 4 adapted to engage and receive said threaded end of a pipe I. Said collar is provided in thepresent instance with a vertical opening 5 square in cross-section adapted to. fit the hollow square reamer shaft 6 slidably extending therethrough. It is obvious that the shaft and opening may be of any desired shape adapted to impart the rotary movement of collar 3 to said shaft. Threadedly mounted on the upper end of shaft 6 is a nut I adapted to coact with the shoulder 8 to prevent disengagement of the shaft from said collar as will be well understood. The

upper surfaces of the nut and shaft are concaved as at I to direct a ball 9 from the drill pipe i to the hollow bore in of said shaft for a purpose hereinafter more fully explained.

Integrally or otherwise formed on the lower end of collar 3 are the equispaced bifurcated lugs ll positioned over the respective sides of the shaft. Adapted for overlying relation with respect to each of the four surfaces of said reamer shaft 8 are respective sets of reamer arms A comprising upper arm sections i2 hingedly connected at their upper ends to lugsl l'by pins l3, and hingedly connected at their lower ends to the upper ends of the lower reamer arms 'or sections H by pins ii, the lower ends of arm sections l4 being connected by pins IE to lugs i1 projecting from the upper edge of the slidable ,collar l3, in a manner similar to lugs II.

The lower ends of the arm sections l4 are formed with cams l9 adapted to seatin the complemental cam-stop recesses 20 formed in the respective surfaces of shaft 3, and which p events downward slidable'movement of collar I! (Fig. 3) during lowering of the device in the well D and until arms l4 have moved to expanded position (Fig. 4). Just below recesses 20 and in alignment therewith, said shaft 8 is formed with the recesses 2|, ending at or near the lower end of the shaft and which correspond in depth and width to the recesses 20, and which are adapted to receive the cams l8 and permit closing of the arms A at any point desired when the lower ends of arms i4 are below recesses 20. Each of the respective arm sections l2 and I4 is formed at i s forward edge with a cutting edge or cutting teeth i4. The respective reaming arm sections l2 are longer than the reaming or cutting sections l4 so that when in open or expanded position the outer ends of the latter at connections i5 will be elevated somewhat with respect to their inner end connections l6 (Figs. 2 and 16) to effect the desired cutting or reaming angle, and distribution of the forces applied to the reaming assembly B during the reaming operation.

Just below the hinged connection ii of the arm sections i2 and i4, and formed in the respective opposed surfaces of shaft 6, are the openings 22 terminating in the downwardly extending recesses 23.

Mounted in the openings 22 and with their rounded and beveled edges 22' converging into meeting engagement centrally of the bore i0 (Fig. '1) are the cam members 25 normally seating in the recesses 23 flush with the surface of said shaft 6. Extending through said shaft 6, spaced from the opposed surfaces of the shaft and in parallelism therewith, are the bores 26, and sim'- ilarly extending through the remaining opposed surfaces and intersecting bores 26 at right angles thereto are the similar bores 21. Inserted in bores 26 and through the cams 24 are the short pins 28 adapted when operatively positioned not to interrupt the bores 21, and inserted in bores 21 and through the remaining cams 24 are the long pins 29, the ends of which are flush with the opposlte surfaces of shaft 6 (Fig. 3). As clearly shown in Figs. 3 and 7, when the reamer arms l2 and I4 are in closed position the earns 24 are likewise in closed position within bore ID. If desired, instead of the

bores

28 and 21, the surfaces of the reamer shaft may be slotted and the

cam pins

28 and 29 welded or otherwise secured therein.

Sometimes when pressure is applied to arms l2 and I4 by collar 3, by reason of said arms being on dead center at joint H5 or otherwise, they fail to move in expanding or opening direction, and in order to insure positive action in such regard the cam '24 arrangement has been provided so that ball 9 (Fig. 5) acting on surfaces 22 under the pressure of the fluid passing through bore I0, is forced between cams 24 elevating cam arms 25 and expanding said arms i2 and I4 at Joint l5, thereby starting the outward and expanding movement of said arms in reaming direction, as will hereinafter be more fully described.

The bottom surface of .upper collar '3 is formed intermediate adjacent lugs l I and at the four corners of opening 5 or shaft 8 (Fig. 13) with the threaded openings 30, each adapted to receive the reduced threaded end 3| of a thrust rod 32.

Each of said rods 32 is formed with a shoulder adapted for detachable connection with a shoe assembly C.

portion and collar 33, depending upon the depth of the well and the location of the oil bearin stratum to be reamed with respect to theshoe assembly at the bottom of the well.

In Fig. 1'1 is illustrated a modified form of" reamer arm structure, similar in principle to the form hereinbefore described, but instead of the two hinged arm structure A, a three articulated or hinged arm structure A is employed.

This form, while not "limited to, is especially applicable to chambers already reamed, the pores of the walls of which have become plugged with The shoe assembly C is adapted, as will directly I more fully appear. to rest on the bottom of 1 a well and support the weight of thereamer construction, and comprises a complementally formed and threaded collar or socket member 33 adapted to receive the tapered end 31 of shaft 3. Said member 33 is formed .with a bore l0 forming when positioned a continuation of bore l3 and which extends to the closed end 39 of the depending cylindrical member 40 formed integrally with said collar 33, and which adjacent its closed end is provided with an annular series of outlet openings 4|. A socket or cup-like member 42 is dimensioned to receive the member 33 and is formed with a reduced externally threaded portion 43 having a bore 44, of slightly greater diameter than the cylindrical portion 40 extending therethrough, to provide the coil or lubricating space 45.

Seating in said socket member 42 is a thrust ball or roller bearing 43 on which is supported collar member 38. The upper end of socket 42 is formed with, the threaded countersunk portion "in which is threadedly engaged the packing ring 48, surrounding collar 38, and adapted to .at its lower end with a plurality of equi-spaced feet members 52 which extend below the bottom element 33 and are adapted to be supported on the bottom of the well. Base member 50 is provided with a central bore 53 adapted to register with and form a continuation of bore 44 and oil space 45. The bottom of said base member is threadedly countersunk surrounding the bore 53 met 54 to receive the'packing ring 55 mounted on the lower end of the cylindrical portion 40 of member 38 for engagement with packing 49, similar to ring 48. It will thus be noted that such shoe construction effects a long bearing surface, extending from packing ring 48 to the packing ring 55, for the reamer shaft 6 supported on the thrust bearings 43 and carrying the reamer struc ture. Also the construction of the shoe and base portion is such as not only to provide a stable supporting structure. but to prevent its bogging down and at the same time effect fluid circulation through the shoe structure to the bottom of the well and thereby maintain thewell at all times clear of the material reaching the bottom from the reaming operation.

It should be noted here that while the threaded reamer end 3'! of shaft 3 and the complementally hardened oil and the" like, and in such cases where no great depth of stratum has to be removed, it will operate more quickly than the form heretofore described. In Fig. 17 there is shown a drill .pipe I, the upper collar 3*,shaft 3 sliding collar l3, and shoe structure C, which are similar to the

parts

3, 3, l3, and C heretofore described. However, in this instance each of the articulated or hinged arms A comprise an upper arm section 33 with its upper end suitably hinged to lug Il and a similarlower section 31 with its lower end suitably hinged as at 38 to the shaft 3", in the present instance. adjacent to shoe C, but'which may be at any desired point spaced therefrom. These arms are connected by an intermediate arm section 59 hingedly connected as at to arm 53, and as at 3| to arm 51, the arm 59 at all times extending in parallelism with shaft 3' whether in folded or overlying position with respect to said shaft or'in expanded position. I

It will be observed that in the present instance there are four sets of these arms A, corresponding to the sets A heretofore described, but for opposed sets. Each of the arms 59 centrally of their length are formed with a pair of ears 32, between which are hinged the outward ends of the upper and

lower brace rods

33 and 34, respectively. The upper end of rod 33 is suitably and hingedly connected to a lug 35 suitably formed on or attached to'the end surface of collar l8, and the lower end of brace rod 34 is hingedly connected by pin 33 to collar 31 suitably anchored or attached to shaft 3-. Suitably connected at their upper ends to collar 3', and at their lower ends to collar l3, are the thrust rods 32 which operate similarly to rods 32 except they are also connected to collar I3 and not only transmit force from collar 3 to collar l8, and outwardly to arms 59 through the

braces

33 and 34 and shaft 3', during ,the reaming operation, but effect synchronous movement of the collar l3 with respect ment of collar 3* onshaft 3" effects moving thearms and braces into folded and overlying relation with respect to shaft 6*, since arms 51 and braces 34 are hingedly secured to, shaft 3*, and in such folded position this form of reamer assembly B is ready for insertion into or removal from a well, the operation in this regard being similar to assembly B. The forward outer edges of these arms are formed with cutting edges similar to arms l4, or as desired. The cam mechanism 24 is also applicable to this form.

Fig. 16'diagramatically illustrates a well D drilled in' ground 38 and with the form illustrated in Figs. 1 and 2 in operative position in process of forming or reaming the chamber E. When the arms A of the reaming assembly B are in closed position as shown in Fig. i, it is evident that the apparatus can be inserted in the well D with the shoe assembly C resting on the bottom of the well, and when rotary movement has been imdevice upwardly.

be below recesses 20, the upward movement of parted to the device, ,chamber E will be formed. While the operation of the device would seem to be clear from the above description, it might be well to further state that when the device is 'wardly on said shaft, and as the cams I! are positioned in cam recesses 20 the lower collar is prevented from moving downwardly. Therefore, the arms A at joint I will move outwardly in expanding direction and in reaming engagement with the wall of-the well until they have substantially reached their expansive limit, as shown in'Fig. 4, and at which time the cams i3 have moved out of the recesses 20, so that as force is applied to collar 3, collar l3 and arms I are moved down in reaming direction, since force is applied directly from collar 3 to arms I! and to collar l8 through thrust rods 32 said collar II and arms are free to move downwardly in reaming direction as shown in Fig. 16. At the same time the reaming structure is supported by the shoe. structure C resting on the bottom of the well, and its formation, including the cleats or feet 52 and bottom 39 tend to prevent it from sinking into said bottom, thereby permitting the fluid stream being pumped through said shaft 6 and the shoe structure to discharge through lateral openings 4! and to carry the reamed material that has reached the bottom of the well upwardly between the shaft 6 and the wall of the well, and from chamber 5, out of the top of the well. This not only maintains the well at all times clean, but the material content of the fluid is entrained with theupward flow as it passes through chamber E by the rotating action of the arms causing an outward motion of the circulating fluid against the walls of the chamber by the whirling movement set up in the fluid which not only effects a continuous passage of the fluid from the well and insures the eiiicient removal of waste material, but lubricates and maintains the cutting portions of the reamer arms cool.

In initially starting the device, the arms l2 and I may not move outwardly by reason of being on dead center or otherwise, and to overcome this difliculty and to insure positive action and immediate breaking of the joint irrespective of the position of the arms, a steel ball 9 is inserted in the drill and fluid supply pipe above the cams 24, and the fluid passing through bore it forces the ball against the cam surfaces 22' which actuates the cams to open position permitting the ball to pass through, and at the same time elevating arms 23 into engagement with arms 13, thereby breaking the Joint and starting the outward movement of the arms as shown in Fig. 5. Also, I might add, that after collar II has moved below recesses 2|, the folding of the arms A may be effected at any point desired since cams ii are free to move into recesses II.

To remove the device from the well, if the cams I! are not below recesses 23, upward movement of the drill pipe and collar 3'fold the arms into parallelism with the shaft, as in the first instance, and head I engaging shoulder 3, pulls the entire However, should the cams ll collar 3 will fold the arms, and-when cams II have reached the upper ends of recesses 2|, being un-' able to pass beyond said ends, the shaft and connected parts will be moved upward as above described.

It is to be noted that theball I, after passing through cams 24, passes with the fluid to the bottom of the shoe and rests on bottom 39 below openings 40 and, therefore, may be recovered for future use when the apparatus has been withdrawn from the well.

From the above description it will be apparent that I have designed an oil well reaming or cutting device which has for its principal purpose the reaming out to a larger diameter of such portions of oil wells as pass through oil bearing strata, in

order to increase the exposed surfaces of such strata and thus induce a larger flow of oil. The entire device is mounted on the reamershaft 3 comprising the reamer assembly B including the upper collar 3, lower slidable collar i3, the sets of expansible reamer arms A, and the shoe assembly C.- The construction of the arms and collar connections is such that while they have free foidable and expansible vertical movement they are prevented from horizontal movement independently of the movement of collar 3. There is means carried by its upper end for preventing shaft 0, slidable through said collar 3 and adapted to extend within the drill pipe I, from separation from said collar which is adapted for detachable connection with drill pipe i. Said device is compact in form, and the weight of the parts below collar 3 automatically eflects folding of the arms with respect to the shaft during the lowering of the device into the well and its withdrawal therefrom, said device being versatile in its adaptive use under varying operating conditions, and especially by reason of the arm assembly 13 being interchangeable with assembly B without necessitating material structural alterations, said device being simple in construction, manufacturable at a reasonable cost, and efficient for the purposes intended.

Although in practice I have found that the form of the invention illustrated in the accompanying drawings and referred to in .the above description as the preferred embodiment, is the most efllcient and practical, yet realizing the conditions concurrent with the adoption of my invention will necessarily vary, I desire to emphasize that various minor changes in details of construction, proportion and arrangement of parts, may be resorted to within the scope of the appended claims without departing from or sacrificing any of the principles of this invention.

Having thus described my invention, what I desire protected by Letters Patent is as set forth in the following claims:

1'. A well reaming apparatus comprising a rotary drive member, a reamer shaft, a reaming assembly slidably mounted on and adapted to rotate with said shaft comprising upper and lower collars, an articulated cutting arm hinged intermediate its length and having its ends atinto a seat formed in said shaft releasable when said arm has substantially reached its predetermined expanded position, and means including a stationary member for rotatably supporting the lower end of said shaft.

2. A reaming apparatus comprising a rotary drive member, a reamer shaft, a reaming assembly connected to said drive member and slidably mounted on and adapted to effect rotation of said shaft and comprising upper and lower collars, collapsible reaming arms having their ends attached, respectively, to the upper and lower collars, co-acting means between the lower ends of the arms and shaft to prevent the downward movement of said lower collar during the expanding movement of said arms but releasable when said arms have substantially reached-their expanded positions, said'means including cams on said arms normally seating in recesses in'said shaft, and means including a stationary member for rotatably supporting the lower end'of said shaft.

- 3. A well reaming apparatus comprising a rotary fluid supply drill pipe, a hollow reamer shaft, 9, reaming assembly slidably mounted on and having rotary drive connection with said shaft and including upper and lower collars, articulated expansible arms operable by the up ward movement of said upper collar intoparallellsm with said shaft and having their ends attached, respectively, to the upper and lower collars, means during the downward movement of said upper collar for maintaining the lower collar fixed with respect to said shaft until the arms have substantially reached their expanded positions, said means including cams on said arms normally seating in recesses in said shaft, means including a stationary member for rotatably supporting the lower'end of said shaft, said stationary member having a central bore forming a continuation of the bore of said shaft whereby a fluid flow is directed through and below said device and stationary member to the bottom of the well.

4. A well reaming apparatus comprising a rotary fluid supply drill pipe, a hollow reamer shaft in communication with said pipe, a reaming as-. sembly slidably mounted on and having rotary drive connection with said shaft and including upper and lower collars, articulated cutting arms having'expanded and collapsed positions attached to said collars, said upper collar being attached to said drill pipe, means including a stationary member for rotatably supporting the lower end of said shaft, said means having a central bore forming a continuation of the bore of said shaft whereby a fluid flow is directed through said device and stationary member to the bottom of the drill pipe and a reaming mechanism operated by said dri-ll pipe, said mechanism including a reamer shaft and a reaming arm assembly slidably mounted on said shaft'comprising a plurality of articulated reaming arms and upper and lower reamer arm carrying collars, the upper collar being secured to said drill pipe, said arms by the upward movement of said upper collar being movable to and normally extending in closed substantial parallelism with said shaft but expansible to reaming position by the downward movement of said upper collar, means for maintaining said lower collar'against slidable movement until the arms have moved to expanded position, said means including cams formed on said arms normally seating in recesses in said shaft. means for limiting the meeting movement of said collars and adapted to transmit force direct from the upper to the lower collar when force is applied to said upper collar in reaming direction, and means for rotatably supporting the lower end of said reamer shaft.

ii. A reaming apparatus comprising a rota y drive member, a hollow reamer shaft, a reaming arm assembly mounted on said shaft having con-' nection with saiddrive member and includini; an articulated reaming arm normally extending in overlying parallelism with said shaft and operable into said position by said drive member and also-by said drive member expansible to reaming position, means for starting the initial outward movement of said arm in expanding direction extending within said shaft, and means rotatably supporting the lower end of said shaft.

7. A reaming apparatus comprising a rota y drive member, a bored reamer shaft, a reaming arm assembly mounted on said shaft having connection with said drive member and including anarticulated reaming arm movable into overlying parallelism with said shaft and expansible to reaming position, by the upward and downward movement, respectively, of said drive member means in connection with said shaft and coacting with said arm to eflect the initial outward movement of said arm in expanding direction, said means including displaceable elements extending into the bore of said shaft and means operable through said bore for displacing said elements, and means rotatably supporting the lower end of said shaft.

8. A reaming apparatus comprising a rotary drive member, a hollow reamer shaft through which a fluid stream is adapted to flow, a reaming arm assembly mounted on said shaft havin connection with'said' rotary drive member and including reaming arms operable by the upward movement of said member into overlying parallelism with said shaft and expansible to reaming position by the movement of said member in downward direction, displaceable means in connection with said shaft co-acting with saidarms andmeans operable through the bore of the shaft for displacing said means to effect starting of the initial outward movement of said arms in expanding direction, and means rotatably supporting the lower end of said shaft.

9. A reaming apparatus comprising a rotary driving member, a reamer shaft, a reaming assembly slidably mounted on said shaft and rotatable therewith including upper and lower collars, a plurality of reaming arms connected to said upper collar and at their lower ends to said lower collar, said arms comprising upper and lower hingedly connected reaming sections, said arms being operable into overlying parallelism with respect to said shaft by the upward movement of said upper collar, but expansible to open learning position by the downward movement of said upper collar, cam means carried by the lower ends of the lower arm sections co-acting with cut out seats formed in said shaft to maintain the lower collar fixed but releasable to permit downward movement of said coller when said arms have substantially reached their expanded position, and means for rotatably supporting the lower end of said shaft, said upper collar being connected to and operated by said rotary driving member and means in connection with said shaft for initiating and expanding movement of said reaming arms.

10. A reaming apparatus comprising a rotary driving member, a reamer shaft, a reaming mechanisni connected to said rotary member and slidably mounted on said shaft and rotatable there- 11 a with including upper and lower collars connected by a plurality of expansible reamer arms, said arms being operable by the upward movement of said upper collar into overlying parallelism with respect to said shaft, but expansible to reamin position by the downward movement of said upper collar, cam means associated with said arms and adapted to seat in recesses formed in said shaft to maintain the lower collar fixed during the expanding movement of said arms, said cam means being displaceable to permit movement of said collar with respect to said shaft when said arms are in expanded position, and additional recesses in said shaft adapted to co-act with said.

cams, when said lower collar has moved below said first mentioned recesses, to permit collapsing of the arms at any desired point with respect to said shaft, and means for rotatably supporting the lower end of the shaft. V

11. A reaming apparatus comprising a rotary driving member, a reaming shaft, a reaming mechanism mounted on said shaft and rotatable therewith, comprising a pair of collars slidable on said shaft, including an articulated reamer arm associated with said shaft and attached to and controlled by the upper collar, said upper collar connected to andcontrolled by said rotary member, said arm being operable into overlying parallelism with respect to said shaft and expansible to open and reaming position by the upward and downward movement, respectively, of said upper collar, said arm comprising upper, lower, and intermediate hingedly connected sections, and means for rotatably supporting the lower end of said shaft.

12. A reaming apparatus comprising a rotary driving member, a reamer shaft, a reaming mechanism mounted on said shaft and rotatable therewith including upper and lower slidable collars, rods interconnecting the collars adapted to transmit force from the upper to the lower collar and to effect their synchronous movement, said v said upper collar and expansible to open. position by the downward movement of said upper collar. said upper collar being connected to and operated by said rotary driving member, and means for rotatably supporting the lower end of said shaft.

13. In combination with a rotary drill pipe, a bored reamer shaft, a reaming arm assembly slidabiy mounted on said shaft and including upperand lower collars, a plurality of reaming'arms attached to said collars, said arms being operable into overlying parallelism with respect to said shaft by the upward movement of said upper collar and expansible to open position by the downward movement of the upper collar, means on said shaft eo'-acting with cams in connection with said arms and normally seating in recesses in said shaft to maintain said lower collar stationary during the expanding movement of said arms but releasable to permit downward movement thereof when said arms have substantially reached their expanded position, additional recesses in said shaft co-acting with said cams to permit folding of said arms at any desired point on said shaft, means carried by said shaft and co-acting with said arms operable to start the initial outward movement of the arms in expanding direction, and a shoe assembly comprising a' stationary base bearing member, a member attached to the lower end of said shaft seating on said bearing member, rotatably supporting said shaft and constituting a journal bearing projecting longitudinally from said shaft through said base.

WILLIAM R. HARBOUR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,317,192 Jones Sept. 30, 1919 1,402,503, Krause Jan. 3, 1922 1,498,463 McCloskey et a1. June 17, 1924 1,544,757 Huflord et al July 7, 1925 2,290,502 Squires July 21, 1942 FOREIGN PATENTS Number Country Date 331,945 Great Britain July 17, 1932