US1344327A - Underreamer - Google Patents

Description

E. C. AND W. W. WILSON.

. UNDEIIIIEAMER.

APPLICATION FILED 050.20, IsI.

1 ,344,327. Patented June 22, 1920.

THEIR ATTURN underreamer constructions.

UNITED STATES PATENT OFFICE.

ELIHU C. WILSON AND WILLIAM W. WILSON, OF LOS ANGELES, CALIFORNIA,- ASSIGNORS T0 SAID WILLIAM W. WILSON.

UNDERREAMER.

Specification of Letters Patent;

Patented June 22, 1920.

Application iled December 20, 1916. Serial No. 138,055.

such as are used for enlarging well holes to permit the lowering of casing therein as the development of the hole proceeds. It is a particular object of the present invention to provide an improved underreamer in which the cutters or expansible and collapsible cutters or members which are usually present in such a device may be capable of a relatively greater range of lateral expan-` sion in accompaniment with a given distance of play lengthwise of the underreamer body. The present underreamer constitutes an improvement upon or modification with respect to an underreamer such as that disclosed by us in a prior application for U. S.

Letters Patent, filed by us Sept. 27, 1916,

Sei- No. 122,481, but it is to be understood that the broad laspects and features of the present invention are not confined in use land adaptation and application to any one particular type and organization of underreamer, but that the same may be embodied in and applied to a wide range of varying 'lhe invention has for further objects the provision of an improved underreamer which will be generally superior in point of relative simplicity and inexpensiveness of construction and organization, taken in connection with durability, freedom from liability to disorder and derangement of parts and features, facility in assemblage and dismantling or disconnecting of parts and features, positiveness and efficiency in operation, and general serviceability. A further particular object of the invention consists in the formaprior to lowering the underreamer to the zone of performance. Certain features of cutter formation incident to their coperatlon with the other features of the construction likewise enter into the present invention.

lVith the above and other objects in View, the invention consists in the novel and useful provision, formation, construction, combination, association and inter-relation of parts, members and features, all as hereinafter described, shown in the drawing and finally pointed out in claims.

In the drawing:

Figure 1 is a longitudinal sectional view,

l partly broken away, and partly in elevation,

of an improved underreamer constructed and organized to embody the invention; one of the cutters or bits being omitted for clearness of illustration;

Fig. 2 is a view similar to Fig. 1 showing the cutters in contracted or collapsed positions, such cutter being shown in expanded working position in Fig. 1; the cutters being shown held temporarily collapsed for introduction within the casing in Fig. 2, in accordance with the present invention;

Fig. 3 is an elevation of the spring-actuated cutter-carrying rod shown in Figs. 1 and 2, the same being in detached position. and being a view at right angles to the plane of vision in Figs. 1 and 2;

Fig. L1 is a side elevation of one of the cutters shown in Figs. 1 and 2 in -detached posi-k tion, looking toward the inner face of the shank thereof;

Fig. 5 is a detail transverse sectional view taken upon the line 905-505, Fig. 1, and looking upwardly;

Fig. 6 is a bottom end or plan view of the body of the underreamer with the cutters land spring-actuated cutter-carrying rod removed; and

Fig. 7 is a detail inner face view of one of the underreamer cutters shown likewise in detached position.

Corresponding parts in all the figures are designated by the same reference characters.

Referring with particularity to the drawing, the underreamer shown therein as embodying the invention com rises an elongated body A providedi with an internal longitudinal bore or chamber 7 and having at its upper end one member 8* of a taperjoint, such member being knownin the art as a taper threaded pin. By this ]o1nt member the underreamer is connected with the sinker bar, jars, or other features of a str ing of tools utilized in the reaming o eratlon, and which string is suspended at t e lower end of the cable by which the underreamer and string are vertically reciprocated in the hole in the reamin operation, pursuant to which the cutters l disposed' at the lower `end of the reamer body are caused to attack the shoulder or annular formation beneath the casing. to chip, cut or break same away so that the further lowering of the casing may be permitted. The lower end of the reamer body A is shown as formed into o1' provided with a chamber 8 or bowl mouth, the walls of which are slightly upwardly and inwardly inclined, and at the extreme lower orifice of which are provided two downwardly ranging opposed eXtensions or lugs 9 constituting inthrust bearings for the cutters and also provided with upper spreading bearings 9a and lower spreading bearings 9b which coperate with the cutters in both the expanding and collapsing actions thereof. Within the longitudinal bore or chamber 7 in the body A, is disposed a spring-actuated rod 10 which is surrounded by a coil compression spring 11 which bears at its upper end upon an adjusting nut 12 threaded to the upper end of such rod 10; and the lower end of such spring 11 bears upon or is seated upon means Z) for assembling together the body A, the rod 10 and its spring 1l, and the cutters B, such means likewise serving as a stop or seat for thelower end of the spring 11.

At the lower end of the rod 10 are provided separate means c and d of operative connection for the respective cutters B with such spring-actuated rod 10.' Likewise, the lower end of the body A preferably adja-y cent to the upper region of the bowl mouth or chamber 8 is provided with a lateral opening or hole 13 accommodating means e for temporarily and positively retaining the spring-actuated rod in depressed position and consequently retaining the cutters B in contracted or collapsed positions, namely, the positions shown in Fig. 2.

Inasmuch as the general formation of the reamer body A and of the spring-actuated rod and its spring, and 4of the means b for assembling together the parts and stopping the lower end of the spring, are either well known in the art or described and disclosed and claimed in said prior application by us filed, or in other applications for Letters Patent previously filed by us, and inasmuch as the present invention particularly pertains to the formation and relative arrangement and mode of operation and principle of action of the lower end of the springactuatedv rod 10 and the means c and d thereon, together with the cutters 'B, and the means e for temporarily retaining the cutters in contracted positions, only brief reference will be made to such well known and heretofore produced features, emphasis and particular description and statement being concentrated upon the features particularly characterizing the` present invention.

As shown, the means b comprise a key 14 which may be passed endwise through a transverse slot 15 in the reamer body A and through a further transverse elongated slot 16 in the spring-actuated rod 10 beneath the spring 11, and held in position by a lng or head 16a at one end of the key which is received within a recess 17 in the reamer body, and, by a cotter pin 18 which is passed through an opening 19 in the other end of the key 14 and engages with the body A exteriorly of the same.

The lower end of the spring-actuated rod 10 is enlarged as shown, in the portion in which the slot 16 is formed, to strengthen the same, and the extreme lower portion thereof, 10, is flattened at its opposed sides to receive in engagement the inner faces of Athe Shanks of the cutters, such. portion being likewise laterally expanded or broadened. This broadening provides for reception of the means c and d, each of which is shown as a separate pivot pin positively seated in such portion 10l and preferably introduced Within a recess therein within which it is firmly welded. These pins, shown as cylindrical, are when seated in their respective openings in or through the portion 10, disposed to project oppositely from such portion 10, and out of registration or coincidence. Eachpin is preferably thus disposed at a separate side of the longitudinal axis of the rod 10, and their axes are parallel. To each of such pins is applied a separate one of the cutters B, each such cutter havi a shank ortion 2() having an inner flat ace 20* an provided with a transversely or laterally elongated or enlarged socket 20b which receives the respective pin cor d, to pivotally center the respective cutter upon and pivotally suspend it from the respective pin and repsultantly from the rod 10, and eccentrically with respect to the longitudinal axis of such rod. Each cutter is mounted upon the pin c or l which is disposed at the side of the longitudinal axis of the rod 10 at which the cutter in the main operates', thus generally disposing the cutter in its working zone in the main at one side of the of the spring-actuated rod. eretofore in lon ritudinal axis ing body portion 20 at the lower extremityl cutter-carrying rod, is one distinguishingfeature of the present invention. Each cutter B is provided with a laterally rangof which is provided the working or cutting edge 20, such body being provided at its upper end with a riding shoulder 20e for engagement with the lower extremity 8a ot the bowl mouth 8 for coperation to transmit the upthrust of the cutter to the body of the reamer; and likewise for engagement with the lower end of the shoe or casing 21 in Fig. 1, to produce collapsion of the cutters upon the beginning of the elevation-of the reamer, which is accomplished by temporary relative movement of the cutters and their rod 10, and the body A. The upper portion of each body 20c is planed off as at 20, at each-side to produce a downwardly and inwardly inclinedv shoulder QOfg which coperates with the respective lower spreadingv bearing -9b upon the respective lug 9; and the cutter body is provided beneath vsuch shoulders 20g with lateral shoulders 20h, the inner faces of which -form bearings coperating with the upper spreading bearings 9*.

The upper spreading bearings 9 are sharply upwardly and outwardly inclined; and the lower spreading bearings 9b partake of a less acute upward inclination.

The means e is shown in the particular form illustrated in the drawing as including a stop pin which is of proper dimension to be freely passed into the opening 13 so that its inner end may be brought within the chamberl 8 and likewise ,within the elongated slot 16 in the sprin -actuated rod 10 when the rod is in lowere position and the cutters are collapsed or contracted. Thus the action of the spring 11 is resisted and the cutters maintained in collapsed or'contracted positions for entering in the casing, until such pin is withdrawn and the springactuated rod is freed. It is manifest that the slot 16 is only utilized to receive this stop pin for motives of convenience and to obviate the necessity of'providing any other receptive. opening for such pin, although such other opening or other complementary formation upon the rod may be provided as desired. jThe shanks 20 of the cutters are formed to complement the upwardly and inwardly inclined inner walls of the bowl mouth 8, to such an extent as to 'produce a proper working fit, and at the same time to permit of pivotal action of the cutters upon their centering pins c and d. These Shanks likewise -impart outthrust to the inner walls of the bowl mouth 8.

The method of use, mode of operation and advantages of the improved underreamer constituting the invention will be understood from the foregoing description, taken in connection with the accompanying drawingl` and the following statement:

he parts of the underreamer are readily assembled together by applying the cutters to the. pivot pins c and d and then introducing the rod 10 with its spring 11 through the bowl mouth 8 'at the lower end of the body and into the communicating bore 7 in the body. Thereupon the spring is pushed up by inserting a suitable implement through the transverse slot 15, and the key is introduced through said slot and the slot 16, with the end thereofy having the opening 19 leading. The lug or head 16a is then brought into its final recess 17 and the cutter pin 18 is passed through the opening 19 in the key. The parts are now held assembled together subject to ready disassembling or dismantling or reversal of the steps thus described, for the purpose of removing the cutters from the springactuated rod to permit replacement, sharpening, dressing or repair thereof, such sharpening or dressing being frequentlyl necessary, due to the heavy service to whic underreamer cutters are subjected. When removing the key 14 a suitable implement is applied to the leading end thereof. yThe key is driven out in the direction opposite to that in which it is inserted. With the parts assembled, the cutters ma now be drawn downwardly into the position shown in Fig. 2, the bearings' 20 riding over the upper spreading bearings 9u and the shoulders 20g, riding down onto the lower spreading bearings 9". The stop pin e may now be introduced within the hole 13 and entered in the slot 16, holding the cutters down against the compression of the spring 11, whereupon the cutters may be introduced within the casing at its upper end, and the underreainer then lowered on the` cable to that point at which the cutters escape beneath the shoe or lower end of the casing.' After the cutters have been so introduced in the casing, the stop pin e is withdrawn from the hole 13, and the spring freed for action to cause the cutters toexpand when brought to the position last stated beneath the casing, the shoulders 20*g riding upwardly over the lower spreading bearings 9, the bearings 20 riding upwardly over the upper spreading bearings 9, causing first an abrupt expanding action of the cutters followed by a finally more modified expanding action, until the riding shoulder 203 is brought into engagement with the upthrust shoulder 8a at the lower end of the reamer body mouth. Inasmuch as each cutter is pivotally mounted in the main at that side of the longitudinal axis of the reamer body in w-hich its path of expansion lies, the expanding action is all utilized for the out ward projection of the body 20c of the cutter, to produce a full and accentuated expansion, which coincides with a minimum upward ride of the cutter over the spreading bearings. Extreme expansion of the cutters is thus provided, insuring a complete reaming action, or the complete reaming away of the annular shoulder or obstruction beneath the casing. This is of high importance in underreaming work, and the invention provides for obtaining such highly important spread or expansion within the small range of play possible or feasible to be accommodated in a tool of the relatively compact or small form or dimensions permitted by the conditions under which its operation and use take place. Likewise, such extreme expansion is permitted in accordance with the invention without diminishing the strength and stress resistance of the working parts, or inviting breakage or failure thereof.

When it is desired to withdraw the reamer from working position, after reaming the desired extent of formation to per mit further lowering of the casing, the underreamer body A is drawn upwardly by the string-carrying cable carrying with it the cutters until the riding bearings 20@ engage with the shoe or lower end of the casing, whereupon the cutters are ternporarily held against vertical movement while the body continues to rise, the relative movement so produced causing the bearings 20h to ride downwardly and inwardly upon the upper spreading bearings 9, and subsequently the shoulders 20s to ride downwardly and inwardly upon the lower spreading bearings 9b. This downward and inward collapsing movement is initiated immediately, avoiding any pinch as between the cutters and the lugs, due to the slight downward inclination of the upper spreading bearings 9, lVith the parts brought to the positions shown in Fig. 2, upward urge being given the underreamer through the cable, the cutters and the correspondingly lowered spring-actuated rod will follow the body upwardly permitting the reamer to be withdrawn from the upper end of the casing.

One further particular advantage attaching to the pivotal suspension of the cutters at opposite sides of the longitudinal axis of the underreamer, consists in the resultant disposition of the cutters each approximately in a vertical plane when in collapsed position. Owing to such disposition the cut to the longitudinal axis of the reamer, re-

sults in unobstructed lowering of the reamer through the casing. One great difficulty attending the use of underreamers has always been this tendency of the cutters to stick and jam in the casing. This tendency has at times rendered it necessary to tie the cutters together before introducing them `through the casing. No such tying or other precautionary measure is necessary with the reamer of the present invention.

t is manifest that many variations, changes and modifications, all with relation to the foregoing description and statement and the showing of the drawing, may be made, in practicing the invention and adapting it to varying conditions of use and service, without departing fromthe spirit of the invention and a fair interpretation thereof.

Having thus disclosed our invention, we claim and desire to secure by Letters Patent l. In an underreamer, a. body and a pair of cutters, the body and cutters having interengaging means for causing expansion of the cutters,cutter supporting and actuating means including a spring actuated plunger having a lower centrally aligned Hat head with opposite parallel faces, the cutters having each a flat laterally offset shank, which shanks fit flatly one against one face and the other against the opposite parallel face of the fiat head, and pivoted connections for the cutters to the head embodying two pivots, one for one cutter at one face of the head and the other for the other cutter at the opposite face of the head, said pivots being parallel to each other and at right angles to the head faces and spaced apart on lopposite sides of a central longitudinal plane perpendicular to the head faces.

Q. In an underreamer. a body and a pair of cutters, the body and cutters having interengaging means for causing expansion of the cutters, the cutters being swingingly movable in a plane of movement longitudinal and central of the body, said cutters ha v ing flat shanks which overlap each other and lie at opposite sides of the central longitudinal plane of movement of the cutters. and cutter supporting and actuating means which include two-pivots upon one of which one cut- In testimony 'whereof We have signed our ter shank is mounted and on the other 0f names to this specification in the presence 0f 10 which the other cutter shank is mounted, said two subscribin Witnesses.

- pivots being'parallel to each other and par- E IHU' C. WILSON.

allel to and spaced apart on opposite sides WILLIAM `W. WILSON. of, a central longitudinal plane which is Witnesses: perpendicular to the longitudinal plane of ALFRED I-I. DAEHLER,

movement of the cutters. C. A. NIMMO.

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