US2740456A - Expander tools - Google Patents

Description

pril 3, 1956 C. LAVALy 1R 2,740,456

EXPANDER TOOLS Filed Oct. 5 1953 4 Sheets-Sheet l f4. f@ :E: @s HOV ib l E /o gw M (D) 35 4" f7, y 3 am; f

|I" I UH. /0 i I J-Ml jle f- 46 E I a@ E EE 23R mi E I 1| 6 I 1 45 E 45g O O 1 E 50 50-4 I 48 CLAUDE A1/,4L JR /NVEA/rof? E HUEBNER, BEEHLER,

WORREL a HERZ/6 ,e1/7 Arm/wey: H6" By 6 M April 3, 1956 c. LAVAL, JR 2,740,456

EXPANDER TooLs Filed Oct. 5, 1953 4 Sheets-Sheet 2 ,2s/e f .I l' t C ma @o @a www April 3, 1956 c. LAVAL, JR 2,740,456

EXPANDER TOOLS Filed OCT.. 5, 1955 4 Sheets-Shee Z5 CLAUDE AVA/ JR.

/NVENTOR HuE/VER, EEHLE/Q,

WOR/PEL a HERZ/G ATTORNEYS April 3, 1956 C, LAVAL, JR 2,740,456

EXPANDER TOOLS Filed OCT.. 5, 1953 4 Sheets-Sheet 4 38 CLAUDE LAVA/ JR.

HUEBNER, @Eem/5R, wom/5L a HERZ/6 A77' ORNE VS` www Unite The present invention relates to expander tools and more particularly to such a tool for forcibly .distending .Qblcts by which it is receivable, such as collapsed or improperly fonned well casings, pipes, tubes, conduits, objects having boreholes and the like.

While the tool has a wide range of applications 'where its powered vexpansion is of use, it was initially produced vfor therepair of collapsed well casings and is conveniently illustrated in connection with such operations. Theshifting of subterranean formations, imbalance of external and internal pressures, and the action of well tools .and operating equipment frequently deform well casings to such an extent that these wells are inoperable until the deformations are rectified. A frequently occurring problem is the collapsing of the casings so that y.their minimum transverse dimensions are inadequate to receive or to ,house operable drilling equipment, pumping apparatus or repair tools.

Although many tools have been devised for the purpose, it is currently the general practice to redrill the portion of the well containing the collapsed casing or successively to drop a pointed weight into the collapsed portion with the hope that the resultant blind hammering alleviates more than it aggravates the pinched condition. Beth practices are of such questionable effect that valuable wells which have been damaged arefrequently abandoned without trying either. The redrilling is time consuming, expensive, damaging to excessive amounts of the casing and frequently results in a departure from the initial bore and the forming of ,a bifurcated well, neither forks of which may be effectively employed nor conveniently isolated from the other. The weight dropping practice usually fails to utilize the momentum of the falling weight advantageously, 4,outward penetration of the casing is common, and much denting andY dimpling results. In the event either operation is successful, it is then necessary to insert a reinforcing sleeve at the position of difficulty .and to ,secure it in a dependable manner. Neither the burred .condition of a drilled casing nor the dimpled and dented state of a weight-hammered casing is conducive to convenient and proper fit-ting of such sleeves.

Of the other tools intended for the purpose, most are even less effective than the practices described .and thus have not generally been accepted; many Vrequire .time consuming lowering and retrieving by means of a tubing string utilized for power supply or control purposes, such string requiring the assembly ,and subsequent disassembly of numerous lengths of drill pipe; and most provide inadequate power to expand collapsed casing, or such ineicient application of available power, as to be ineffective except in most opportune situations. Further, even though casing faults frequently occur at great depths and at positions of extreme uid pressures, none have recognized nor been adapted to these additional difticulties and .several are rendered inoperable thereby. For example, the inaccuracies of the droppi-ng are considerably increased and its impacting power immeasur- :ably decreased .by its falling through liquid `for substantial distances before exerting its striking force. The usual confining of well liquids in casings causes the liquids to retard rapid movement of such weights yeven more, than Enright otherwise occur.

An object of the lpresent invention is to provide an improved expander tool successfully operable forcibly to distend collapsed, improperly formed, and/or incompletely shaped well casings, pipes, tubes, conduits, vbore- :holes :and the like.

Another object is to provide an expander tool that can .hespeedily and easily lowered vinto a well or -the like to, an operating depth and retrieved therefrom.

.Another object is to provide -an `expanderztool that isgaccurately and dependably remotely controlled.

Another object is to provide a tool-of the 'character described that -can be suspended ona cable for ease :and :speed of lowering and raising and .that is fully controllable vwhileso suspended.

Another object is to provide Aa well casing tool which `is capable-tof operating etiiciently at ,extreme we'l'l depths. More .specifically it is an object to design the tool :so that it can withstand high environmental pressures as en- -countered in deep wells without significantly impairing .operational accuracy or eiciency.

Another object is `.to provide a well tcasing tool consisting of a ,self sucient unit including a housing,a working memberexternally ofthe yhousing,.and'equipment yfor .operatingthe working .member contained inthe housing.

Another object is to provide .a well casing tool'of a .construction which insures its lowering tinto, fand'from, Well casing without danger of wedging or stickingY therein.

Another object is to provide a well casing tool which is capable of exerting large lateral pressures against 'the sides of a `collapsed well casing without jarring or hammering the casing and incurring the hazards and `damages .incidentthereto These, and other objects of this invention `will become more fully apparent upon reference to the following vdescription and accompanying draw-ings, in which:

Fig. 1 is a side elevation of an expander tool embody-V ing the principles of this invention shown supported in .a well -casing illustrated in vertical section.

Fig. 2 is a view similar to Fig. 1, ybut showing a portion of the expander tool brokenv away permitting observation of the interior thereof.

Fig. 3 is a fragmentary diagrammatic view of Ythe tool and a hydraulic actuating system therefor. l

Fig. 4 is a somewhat enlarged fragmentary view similar to that of Fig. 2 but showing a portion `of the tool in section on a plane ninety degrees removed from Ythat of Fig. ,2.

Fig. 5 is a fragmentary side elevation of the portion of the tool shown in Fig. 4, certain element-s there'o'f'being sectioned for illustrative convenience.

Fig. 6 is an enlarged fragmentary section taken online 6 6 of Fig. 1.

Fig. 7 is a View similar to Fig. 6, showing elements of the tool in a successive stage of operation.`

Fig. 8 is an enlarged fragmentary section taken on line. 8-8 of Fig. 4 showing internal details of a hydraulic control valve utilized in the tool.

Fig. 9 is an enlarged section taken on line 9-9- of Fig. 5.

Fig. 1'0 is a transverse section of the tool taken at the position indicated at 1li-10 in Fig. 6.

Fig. 1l is a transverse section taken atthe position indicated at 11-11 in Fig. 6.

Fig. 1.2 is an end elevation of theexpander .tool viewed from the working end thereof.

Fig. '13 is a transverse section taken at the position indicated at 13--13 of Fig. 4 showing a reservoir for operating iluid.

Fig. 14 is a section of the reservoir shown in Fig. 13, viewed from a sectioning plane ninety degrees removed from the sectioning plane of Fig. 13, as shown by line 14-14 in Fig. 4, and with elements of the reservoir in a successive stage of operation.

Fig. 15 is a transverse section taken at the position indicated by the line 15-1S in Fig. 4.

Fig. 16 is a longitudinal section of a pump used in the hydraulic system of this invention, taken on line 16-16 of Fig. 4.Y

Fig. 17 is a section of the pump of Fig. 16 taken on line 17-17 of Fig. 5.

Fig. 18 is a section taken on line 15-18 of Fig. 5

Referring more particularly to the drawings, the numeral l@ in Fig. l denotes a portion of a well casing containing therein a fluid 12 such as oil or water. Supported by a cable 14 is an elongated torpedo-shaped housing generally indicated by the numeral 16. The

housing 16 is constructed of a heavy gauge steel or the like having adequate strength to resist damage thereto as well as to the equipment contained therein as a result of fluid pressure on the outer wall thereof or abrasion with objects of an operating environment such as a well casing. While it is to be understood that the tool may be employed in any desired attitude, it is conveniently described in the pendant position shown in the drawings. The housing 16 is divided into an upper section 18 and a lower section 2t). The upper section l consists of an elongated hollow cover portion 22 having a streamlined upper snap-on or loosely tting closure member 24. The cover 22 is further threadably attached at its lower end in uid tight engagement to a boss 26 on the lower section 29. The closure member 24 is provided with an opening 2S for receiving the cable 14 and other control wires subsequently to be described. The closure member is preferably not fixedly attached to the housing, as by threads, in order that it may be easily removed in an emergency so that access may be had to the supporting bracket described below, by heavy grappling tools or the like.

The threaded boss 26 is also used for supporting on its top surface an elongated iiat plate member 36 which in turn mounts the various elements within the upper section 18 of the housing subsequently described. The plate member 30 is secured at its top against movement by a transverse bar 31 extending laterally from the plate and abutting against the cover 22 when in position, thus providing a three-point contact for the plate within cylindrical cover 22. A U-shaped supporting bracket 34 for the purpose of attaching the cable 14 or other grappling hook thereto is secured to a plate 32 threadedly received in the upper end of housing cover 22.

A hydraulic system is supported on plate member 3i) and consists of an upper reservoir 36 near the upper end of member 30, an electric motor 3S mounted beneath the upper reservoir, and a speed reducing transmission system 40 connected between the output of the motor 38 and the input of a luid pump 42. Beneath the fluid pump 42 and also supported on plate Fail is an electrically operated fluid control Valve 44. The operation and association of the various elements in the hydraulic system is best understood by reference to Fig. 3, and will subsequently be referred to in detail.

Referring in particular to Figs. l, 2, 6 and 7, attention is devoted to the lower section 2? of housing i6. This portion of the housing consists of three main parts, an upper steel casting 45 within which is formed a cylinder 46 and which is threadably secured to a lower casting 47 in fluid tight engagement. A plurality of segmental arms or jaws 48 are pivotally attached to the lower end of casting 47, as at 50, and depend downwardly when relaxed cooperatively to form anose on the housing.

Mounted for reciprocaticn within the cylinder 46 is a d ram or piston 52 connected at its underside, as viewed, toa rod 54. Motion is transmitted from rod 54 to the ngers 48 through a lower head or piston 58 and connecting rod 56, its associated head 57 and a set of links, the details of which will subsequently be described.

The general operation of the invention thus far described is as follows. The housing 16 is lowered within the Well casing 10 by means of the cable 14 to a desired depth of operation. By means of electrical control wires to be described, the motor 3S and valve 44 are energized whereupon lluid pressure is built up in the hydraulic system. This pressure is transmitted from the upper seotion 18 of the housing throughY any appropriate passage in the lower section 20 of the housing and into cylinder 46. This pressure acts to depress the piston 52 whereupon connecting rods 54 and 56 are moved downwardly thus transmitting motion to the fingers or arms 48. to move them laterally outwardly against the inner wall o f the casing. When the casing has been properly straightened, the supply of electrical energy is interrupted thereby de-energizing motor 38 and valve 44 whereupon the ram S2 is elevated and the fingers 4S are collapsed.

Referring to Figs. 3, 4 and 5, a more specific description is given of the construction and operation of the hydraulic system. Motor 38 receives its electrical energy from a pair of wires 7d connected thereto and which k extend along with cable 14 through opening 28 to the surface of the well. While two wires are normally utilized, it will be apparent that even a single wire will suftice with the circuit being completed to ground; Although not shown, a suitable source of voltage is usually available or provided at the top of the well for connection to wires 7G. The output shaft of motor 38 is connected to an intermediate shaft 72 having a universal drive joint at each end thereof. The latter connects to a speed reducing transmission box 40, the specic details of which are not important to this invention although represented in Fig. 4 as consisting of a worm gear 74 and associated spur gear 76. The obvious purpose of the transmission is to give the motor 33 a mechanical advantage over the pump 42. While a wide range of vara7 tions in motor power, pump capacity, and reduction ratio of the transmission can be employed, it is appropriate to observe that an embodiment of the subject invention utilizing a loth horsepower motor and a transmission having a reduction ratio of the order of approximately 700-1 has proved excellently suited to the purpose and has developed a lateral thrust by the spreading lingers 48 of approximately one hundred tons, which experience has shown is tar greater than normally required in correcting collapsed Well casings.

The spur gear 76 is mounted concentrically on a shaft 77 rotatably mounted in the transmission and having eccentric journals at opposite ends thereof. A lever 78 is rotatably mounted on each of the eccentric journals of the shaft and extended therefrom in substantially parallel relation. Each of the levers has an extended end pivotally connected to a bell crank 80 pivotally mounted on the channel support member 30, as at 81. The bell cranks provide arms extended toward the pump 42. The pump provides an operating handle 82 extended toward the transmission 4d which actuates the pump when piv otally reciprocated. A toggle link 83 interconnects the extended ends of the arms of the bell cranks with the extended end of the operating handle of the pump. It will be seen that upon rotation of the shaft 77, the lever 78 oscillates the bell cranks 89 to actuate the handle 82 by means of the links 83.

The pump 42 comprises a cylinder portion 84, as seen in Fig. 3 and Figs. 16 to 18, for slidably and reciprocally receiving a piston 86, the latter being coupled to the handle 82. Thus pivoting action of handle 82 reciprocates the piston 86 in cylinder 84. The pump is provided with inlet and outlet ports 9i) and 92, respectively, the former being connected to a second reservoir 94 which forms an 5 integral portion of pump 42. Pump 42 has a pressure relief valve 91, shown in Fig. 18, and check-valves 9.3 and 9S, shown in Figs. 16 and i3, which are for ,theusual purposes.

As previously noted, the electrically operated control valve 44 is mounted beneath the pump 42. This valve hasa chamber 96 formed therein which is connected by means of a ud conduit 93 to the outlet port.-92; Inaddition, the valve provides a bore 99 therein adjacent to the chamber. Chamber 96 has an outlet port or uid passage 100 opening into the bore which may be opened or closed depending upon the position of a valve member 162 mounted for sliding movement in bore 99 against the action of a spring 101. As shown in Fig. 3, the valve member 102 is provided with a reduced diametrical portion 103 intermediate its ends which, if aligned with port 100 and a port or fluid passage 104 at the opposite side of the bore, permits fluid communication between said ports. Port104 is connected'to the second reservoir 94 by means of iluid conduit 106. The chamber 96 of the control valve 44 is also connected for uid flow to the cylinder 46 by means of conduit 108. Electrical control is provided for the valve 44 by means of a solenoid 110 which is mounted on a plate 111 extending from the valve, as best seen in Fig. 8, and which receives its energization from line 70. Solenoid 110 is conventional in construction, having an armature which bears against one arm of a bell crank lever 112 pivotally mounted so that the other arm abuts against the outer end of valve member 102. When solenoid 110 is in a de-energized condition, the valve member 102 is in the open-port position-,shown in Fig. 3, being urged into this position by a spring 113. When the solenoid is energized, the bell crank pivots clockwise against the action of spring 113 thereby permitting valve 102 to slide outwardly under the nuence` of spring 101. it will be` noted that reservoir 36 is connected to reservoir 94 by means of conduit 114 and c0- operates therewith to insure a proper supply of uid in the hydraulic system. The two reservoirs can be incorporated into one but the construction shown has proved convenient and suited to the utilization of conventionally available materials in the restricted spaces of the housing. An inflatable bag or envelope 1-16 is provided within the upper reservo-ir 36 and isnormally in a substantially deflated condition, as shown. Wheniluid is drawn from this reservoir, bag 116 distends, as shown, in Fig. 14 to permit the drawing of iluid from the reservoir without operating against a vacuum. A free air pocket would have the same capabilities but should be isolated from the hydraulic iluid to avoid entering the system and imparting an undesirable resilienceto-theoperation incident to the compresssibility of air. A Huid conduit 11S is provided with a valve and is connected to reservoir 94 for the purpose of filling this reservoir with the hydraulic lluid to be used. A similar conduit and valve, indicated at 120, are provided for lilling reservoir 36.

Referring to Figs. 6, 7, and l to l2, the specific construction of the lower section 20 of the housing is readily described. The upper casting 45 of this lower section is provided with a vertically extending uid conduit passage 200 which is attached at one end to the conduit 108 and opens .at the other end into the cylinder 46. The'piston 52 appropriately employs a plurality of cup leathers 202 mounted on a body member 204 in the well-known manner. The connecting rod 54 is rigidly attached at its upper end to the piston S2 and extends downwardly for sliding movement within bore 20S formed in the lower casting 47. A spring 210 is optionally provided between the lower end of ram 52 and the upper end of casting47 to urge ram 52 toward its uppermost position. The connecting rod 50 abuts against the head 53 of lower connecting rod 56 and is loosely connected thereto by means ofja pair of ear members, as212, extending upwardly-from diametrically opposite sides of the head S and having elongated openings therethrough into-which pins213 ex- .tending laterally from the rod are received. This .arrangement is such that during the downward stroke. of the ram 52 connection between rod 54 andrheadSS isfby abutment thereby permitting a limitedamountofswivelling to occur in the rod 56 as well as eliminating cornpressional strain on the pins 213 or ears 212. During the upward lstroke however, the rods 5.4 and 56 are connected by the ear-and-pin arrangement to retract the lower connecting rod. It will be understood however, that since direct coupling of the rods only occurs in tension i. e. during the upward stroke, severe forces vtending to shear the pin are'avoided.

Toaidin retracting the piston 58, a compressionspring 214 is optionally provided in the bore 208 below the piston. A ball check valve 215 is provided in the side of casing portion 206 and leading into bore 208 `for a purpose to be subsequently described.

The specific construction of the arms 48 is best shown in Figs. 6, 7, and 1'0 through 12. Each of the arms constitutes a longitudinal segment of a generally acutely paraboloidal extension of the housing 16 which when nested, as shown in Fig. 1, presents a streamline lower end for the housing 16. The lower end of each of the arms has an inwardly curved nose portion 216 which has its outer surface roughened as by theprovision of transverse, casev hardened ribs 217 for the purpose Io gripping the sides of the well casing or other work piece. Each arm is pivoted to-the casting47, `as at 50, and optionally has a light spring 218 attached on the inner side thereof to a point on casting 4'7 inwardly of its re,- spective pivot. Likewise, each arm has an arcuate transverse recess 219 in the nose portion 216 thereofvwhich, when the arms are collapsed, asin Fig. 6n1ates withpan adjacent recess in an adjacent arm to form a continuous annular groove. A light spring 220 is placed in this groove and together with springs 218 comprise means for preventing arms 48 from moving out of their-collapsed position in a haphazard manner while transporting the well casing tool above ground, wheninserting and lower ing it into the well and when raising it from the well.

Each arm 4S is also provided with an open socket222 best seen in Figs. 7 and 10 at a point immediately above the nose portion thereof. Each socket 222 is constructed to releasably receive the ball shaped end of a link 224,. Although the links may be actually pivotally. or swivelly connected to their respective arms, the releasable associ ation described is an assembly convenience and adequate for the exertion of outward thrust on the arms, no retractive force or tensioning of thelinks being required. This is more clearly ascertainable from Fig. 7 where it will be evident that sockets 222 provide a wide arc of vertical movement as well as a limited amount of swivel movement for link 224.

Because the well tool of this invention is frequently used in a vertical position such that they arms48 hang downwardly from the body of thehousingit willbe apparent that when the expanding pressure is released, from the arms, they tend, due-to gravity and external environF mental pressure, to collapse from a positionA such as shown in Fig. 7 to the position shown in Fig. 6. This collapsing is also aided by the springs 218 and 220-alf though the more prominent purpose of these springs` is to hold the arms in a collapsed condition whentransportf ing the tool. Thus a removable association between each link 224 and its respective arm 48 has been found satis* factory and as notedabove olierscertain advantagfsv over a xed connection.

Each link 224 is also provided with a ball 226 at its inner end which is receivable in a socket 228 in a base 230 formed on the rod 56. kThe sockets retain the ball end of the links therein :but permit limited swivelling movement thereof and in particularl a relatively wide vertical arc of movement, again asseenbest in Fig.l 7. The upper ledge of each socket 228 and the lower ledge of each socket 222 cooperate in establishing a limiting means for spreading movement ol the arms 48, as will be apparent.

lt should be understood that housing 16 is made as completely fluid tight as possible throughout. However, it has been found desirable to fill the upper section l with a dielectric fluid 233, such as transformer oil, for the purpose of resisting external pressures existing at extreme well depths as well as providing a pressure externally of the hydraulic system which tends to minimize leakage thereof. The presence of the fluid also excludes oxygen and thus obviates the possibility of a lire within the housing. Pressure equalization is obtained between the inside and outside of the housing by providing a flexible diaphragm 232 in a small area of the cover 22. As the pressure increases or decreases on the outside of the housing, this diaphragm exes to equalize the pressures and thus prevents undue strain on the housing walls and compensates for any comprcssibility of the iluid incident to gas dissolved therein.

Operation ln operation the tool is lowered in the faulty well casing to the desired depth of operation or positioned in any other desired work piece, whereupon motor 38 and solenoid 11i) are energized by the closing of a switch, as 234, located at the surface of the well thereby supplying voltage to line 7i). Rotation of *te motor 33 causes the operating handle 52 to move in and out thereby reciprocating the piston 86. Hydraulic luid is drawn from the reservoirs 36 and 94 through inlet port 9i? into cylinder 8e and thereupon. out the port 92 and into chamber 96 through the conduit 93. ince the solenoid il@ has been energized the valve member i152 is in the port-closed position preventing 'the passage of fluid from port li to port ldd. Therefore, uid must flow out of chamber 96 through conduit 14.*3 and into the cylinder 46 through passage Zilli. When sullicient pressure is built up in the hydraulic system, piston 52 is moved downwardly and thereby, through connecting rods 54 and 56, the arms 48 are expanded or spread outwardly. As lluid is pumped from the reservoir 36, the partially gas lled bag 116 expands to replace such removed iluid. rl`his not only makes possible the fluid removal from the reservoir in the closed system but creates a reduced pressure in the reservoir which tends to draw the pumped tluid back into the reservoir when the pump is deactivated.

When it is desired to collapse the arms d8, switch 234 is opened thereby dez-energizing the motor 3S and solenoid 110. Since the motor 3d is static, pump d2 will cease to increase pressure in the system. When the solenoid 110 is de-energized, the valve lil?. moves into the port-open position establishing fluid communication between chamber 96 and the conduit 166. Thus, as piston 52 moves upwardly under the urging of spring 2li), it forces uid through conduit 168 into chamber 96, through the now open valve HB2, into conduit 1%6, back to reservoir 94, and through conduit lid to reservoir 36. Fluid cannot flow from chamber 95 bacl; toward pump 42 in conduit @S duc to the closed condition of valves El and 93. Upward movement of the piston 52 causes both connecting rods 5d and 56 likewise to move upwardly thereby removing the outward pressure exerted on. the arms through links 224. This permits the arms 4.8 to move inwardly to a collapsed position as described above whereby the tool can be removed from the well casing.

It is appropriate to observe, that the principal retractive effects are those of the gravitational tendencies of the arms 4S to return to nested relation, shown in Fig. l, and the automatic lay-passing of the pump 42 by the control valve d4 so that hydraulic fluid h1 the cylinder can discharge back to the reservoirs incident to the existence of greater pressure inthe cylinder i6 than exists in the reservoirs from which the fluid has been pumped. Further, the jarring of the arms '33 against the casing 1i) 8 Y as the tool is pendantly supported therein tends to retract the arms. Of secondary retractive effect are the springs 220 and 218 which possess utility but which are optionally employed. The spring 210 is of course of aid in retracting the piston 52.

lt should be noted that although 0-rings 241 are shown about the rod 56 and head 56, they act to filter the uid rather than prevent its flow. To prevent this leaked-in fluid from collecting under ram :'52 and creating an upward pressure during the downward stroke, pressure relief valve 23.5 has been provided. Because of the uni-directional characteristic of the cup leathers 262, this fluid also occasionally leaks by the cup leathers 202 and into the space above piston 52. When the tool is being lowered into or removed from a well, the hydraulic system is in a static condition and therefore there is no downward fluid pressure in the conduit 168. Thus the well uid leaking into the lower section of the housing and by the cup-leather, as above described, tends to build up a pressure in the hydraulic system and unless provision is made for its release, eventually the pressure created on the top of the piston S2 becomes large enough to depress it. It is believed to be clearly apparent that it this were to happen the ngers 48 would expand thereby locking the tool at some undesirable position in the hole during the lowering or raising operation.

To prevent this action, a pressure relief diaphragm 246 is mounted in an extension 247 of the upper reservoir 36 which projects to the exterior of the housing 16, as best shown in Fig. 5. When well fluid leaks into the upper portion of cylinder 46 above the piston 52 and thereupon into the hydraulic system through passage 28? it does not remain trapped in this position but instead creates a pressure in reservoir 36 through conduit 36S, chamber 96, open valve 102, conduit N6, reservoir 94, and conduit 114. This pressure acts to distend the diaphragm 246 so that such pressure tending to expand the arms is relieved, and the danger of inadvertent locking in the well is obviated.

Diaphragm 246 also has a conjoint effect with inflatable bag 116 of flexing inwardly during actuation of the hydraulic system` and thus aids in preventing air pockets from forming therein, as discussed above, as a result of gas dissolved in the hydraulic lluid.

Although the invention has been herein shown and described in what is conceived to be the most practical and preferred embodiment', it is recognized that departures may be made therefrom within the scope of the invention, which is not to be limited to the` details disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent devices and apparatus.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

l. An expander tool comprising an elongated housing, said housing having upper and lower sections, said upper section being substantially hollow; a iluid communicating duct between said upper and lower sections; means connected to said lower section and being laterally expansible for engagement with a well casing; hydraulic pressure means supported in said hollow upper section for actuating said expansible means and comprising a lluid pump, a reservoir connected to said pump, and a valve connected to said pump, reservoir and duct and having two positions of operation whereby in energized position fluid is permitted to fiow'only from said pump into said duct and in the de-energizcd position fluid is permitted to dow only from said duct into said reservoir; and electrical means for energizing said pump and valve.

2. A well casing tool comprising an elongated fluidtight housing, said housing having a cylindrical chamber therein and a central bore axially extended from the chamber, a ram mounted for recprocation in said chamber, a plurality of depending segmental arms pivotally attached to said housing and being laterally extendable therefrom, linkages associated with the arms, connecting ama-ane rod means extended through the bore between` said ram and each of said linkages for transmission or? movement therebetween,` electrically controlled hydraulic means in said housing, and a uid communicating duct connecting said chamber with said hydraulic means, said hydraulic means being adapted to establish a llud pressure in said chamber for depressing said ram and extending said arms.

3; A well casing tool comprising an elongated iluidtight housing, said housing being divided into removably connected upper and lower sections, means connected to said upper section for lowering said housing into a ilud containing well casing, said lower section having interconnected upper and lower portions, a cylindrical chamber formed in said upper portion and a central bore formed in said lower portion, a ram reciprocally mounted in said chamber and having a connecting rod extending therefrom into said bore, a plurality of segmented arms pivotally dependingly attached to said lower portion and laterally spreadable into engagement with the well casing, linkage means associated with each of said arms and with. a further connecting rod extending into said bore, said last mentioned connecting rod being provided with a headed member in abutting relationship with said first mentioned connecting rod, electrically controlled hydraulic means in said upper section, and a iluid communicating passage connecting said chamber with said hydraulic means, said hydraulic means being adapted to establish a iluid pressure above said ram in said chamber whereby to spread said arms by depression of said ram.

4. A well casing tool for repairing the interior of a Well casing comprising an elongated fluid-tight housing, said housing having upper and lower sections; a plurality of segmental expanderV arms dependently pivotally mounted on the lower section of said housing and adapted upon expansion to engage the interior of a well casing; means ferlowering said housing into a iluid containing well casing; the lower section having a cylinder formed therein; a piston mounted for reciprocation in said cylinder', means connecting the piston to said arms for controlling the expansion thereof; a hydraulic system mounted within said upper section including a fluid pump, a motor kfor driving said pump, a reservoir having a supply of iluid therein, and an electrically operated tluid control valve, said pump having inlet and outiet ports;` lluid conducting means connected between said outlet port and said valve, between said inlet port and said reservoir and between both said cylinder and reservoir and said control valve; and electrical conducting means extendihle out of said housing and connected to said motor and control valve for supplying power thereto whereby upon energization of said motor and valve tluid is forced from the pump through the valve and into the cylinder for depressing the ram and expanding the arms and upon de-energization of said motor and valve, fluid is forced from the cylinder through the valve and into the reservoir permitting elevationof theram'and collapse of the arms.

5. A well casing tool comprising an elongated ilu'idtight housing, said housing being divided into upper and lower sections, said upper section being substantially hollow; means connected to said upper section for lowering said housing into a fluid containing well casing; said lower section having interconnected upper and lower portions, a cylindrical chamber within said upper portion and a central bore formed in said lower portion; aV piston reciprocally mounted in said chamber and having a con= necting rod extending therefrom into said bore; a 'second connecting rod slidably mounted in the bore; a plurality of segmented arms pivotally dependingly attached to said lower portion and laterally spreadable. into engagement with the well casing; linkage means associated with each of said arms and with the second connecting rod; said second connecting rod being provided with a headedmemb'er in abutting relationship with said rst mentioned connecting rod; a iluid pressure establishing means supported in the upper section for spreading said arms, said pressureV means including vva uid pump, a" fluidi-supply reservoir connectedto said pump, and a iluidicontrolfvalve connected to ea-chV of saidrpump,`A reservoir and chamber and constituting a by-pass for iluid flow byrsaitlgpump during the inoperative condition thereof; the'enpergization of said pump and valveI being synchronized and being electrically controlled remotely from saidshousing.A

6. In a remotely controlled tool, the combination.y of a housing, workpiece engaging means mounted: on vthe housing for movement between av workpieceengaging position and a retracted position, an hydraulicframgmount;n ed in the housinghaving controlled connectionf to the workpiece engaging means, a reservoir for hydraulicdiuid, an electrically energized pump connected-tothe reservoir., electrically controlled r'neansvhaving iluid connectionto thepump, to the ram, and tothe reservoir, said electrically controlled means .having an energizedconditionin which fluid passage therethroughrfrom the pumprtothe ram is provided and a de-energized condition inuwhioh fluid passage from the ram` tothe. reservoir in.,.byp,ass relation to the pump is provided., and en .electrical system connected to the pump andvto the electrically. controlled means adapted concurrently to energize and todesenergize the same.

7. in a remotely controlled tool, the combination= of a housing, workpiece engaging means mounted onl the housing for movement between a workpiece. engaging position and a retracted position, meansresiliently` urging the workpiece engaging means into retracted rpositiorgan hydraulic ram mounted in thehousing having controlled connectionto the workpiece engaging means, a reservoir for hydraulic iluid,.an electrically energized pump. con.- nected to the reservoir, electrically controlled ,means,having fluid connection to the pump, to the ram; andlothe eservoir, said" electrically controlled meansy havingV an energized condition in whichlluid passagetherethrough from the pump to the ram isprovided and a, de-energized condition in which ,lluid passagefrom theramto thereservoir in by-pass. relation to the pumpis provided, andran electrical system connected to thef pump and to the electrically controlled means adapted for connection to,.a source of electrical energy remote from thehousing. and disconnection therefrom whereby thepurnp andv tht-electrically controlled means are concurrently energized and de-energized.

8; An expander tool comprisingan elongated housing having a cylindricalcha-mber formed therein and acentra'l bore axially extended from the chamber, a Vpiston reciprocally mounted inthe chamber and having apiston rod extended therefrom intothe bore, a.plurality offsegf mental expander arms `pivotally dependently attached. to the housing andv laterally spreadable therefrom, a con nectingj rod extended into the bore having an. endfin abutting relation with` the pistonrod, linkage means interconnectingfthe arms andthe connecting rod, andelcc-V trically controlledjhydraulic.means mountedinthe housing having iluid connectionfwith the chamber, the hydraulic means beingadapted to establish a. tluidA pressure in the chamber endwardly of the piston whereby the pistonis movedand-through the piston-rod, connect ing rod, and linkage means-the arms are laterally spread.

9. A remotely controlled expander. tool comprising`-ta housing providing a chamber, a pistonslidably fitted to the chamber and reciprocal therein, means. connectedto the housing laterallyexpandable `therefrom to engagea workpieceto be. expanded, actuating meansfconnectingcthe laterally expandable means to the piston,A a `source of hydraulic fluida pump having an. inletconnected.- tothe source of. hydraulic lluid and an outlettconnected torthe chamber operable1 upon actuation to force fluid into the chamber to extend theipiston and therebyy to actuatethe laterally expandablemeans, anielectrical lvsystem: connected to the pump for actuation thereof uponenergization. of the system, switch,. means for energizinggand de-energizin'g the electrical"` system, and tluid control/means. interv4 connecting the chamber and the source of hydraulic uid responsive to energization of the electrical system for blocking lluid ilow between the chamber and the source of hydraulic tluid and responsive to de-energization of the electrical system for permitting such liuid ilow.

10. A well casing tool comprising an elongated housing adapted to be lowered into a well casing, laterally expansible means connected to the housing for engagement with the well casing, a ram in the housing connected to the expansible means for actuation thereof, a liuid reservoir in the housing, a pump having a fluid inlet connected to the reservoir and a uid outlet connected to the ram, means permitting unidirectional lluid ow from the reservoir through the pump to the lluid outlet, a valve mounted in the housing having iluid connection to the ram and to the reservoir and having a first position blocking fluid passage between the reservoir and the ram and a second position permitting liuid passage between the reservoir and the ram, resilient means urging the valve into said second position, and an electrical system connected to the pump and to the valve having an energized condition adapted to actuate the pump and to urge the valve into said rst position and a Cle-energized condition adapted to de-energize the pump and to tlc-energize the valve for movement of the valve by the resilient means into said second position.

1l. A remotely controlled expander tool comprising a housing providing a chamber, a piston slidably reciprocal in the chamber, means laterally expandable from the housing to engage a workpiece to be expanded, means connecting the laterally expandable means to the piston, a source of hydraulic liuid, a pump having an outlet connected to the chamber and an inlet connected to the source of hydraulic fluid, a two-way lluid control valve interconnecting the chamber and the source of hydraulic uid having an open position permitting lluid flow from the chamber to the source of hydraulic fluid and a closed position blocking such lluid llow therethrough, resilient means urging the valve into open position, electromagnetic means operable upon energization to urge the valve into closed position and upon de-energization to free the valve for closing by the resilient means, and electrical control means for synchronously energizing and deenergizing the pump and the electromagnetic means.

l2. A well casing tool comprising an elongated uidtight housing providing a cylindrical chamber therein; a piston reciprocally mounted in the chamber; means connected to the housing laterally expandable to engage the interior of a well casing; means for elevationally positioning the housing in a lluid containing well casing; means connecting the piston to the laterally expandable means for controlling the expansion thereof; an hydraulic system mounted in the housing including a iluid reservoir, and an electrically driven lluid pump having an inlet connected to the reservoir and an outlet and being adapted when energized to cause uid passage therethrough from the inlet to the outlet; an electrically operated iluid control valve having a common uid connection to the outlet of the pump and to the chamber and a separate uid connection to the reservoir, the control Valve including a member positionable to permit fluid communication between the common and separate duid connections when the Valve is :le-energized and to block such fluid communication when the valve is energized; and an electrical system for operating the pump and the control valve including a switch remote from the housing having a closed position for concurrently energizing the pump and the control valve and an open position for concurrently energizing the pump and the control valve.

13. A well casing tool comprising an elongated uidtight housing providing a cylindrical chamber therein, a piston reciprocally mounted in the chamber; means connected to the housing expandable laterally of the housing to engage the interior of a well casing; means for controllably positioning the housing in a uid containing Well casing; means connecting the piston to the laterally eX'- pandable means for controlling the expansion thereof; an hydraulic system mounted in the housing including a lluid reservoir, and a uid pump providing an inlet having fluid connection to the reservoir and an outlet; a uid check valve in the liuid connection between the reservoir and the inlet of the pump adapted to preclude fluid llow from the outlet to the reservoir through the pump; an electrically operated iluid control valve providing a bore having uid connection to the reservoir and providing a uid chamber having fluid connection to the outlet of the pump and to the cylindrical chamber in the housing and having a port opening into the bore from the liuid chamber, a valve piston slidably mounted in the bore for vmovement between a position permitting fluid passage through the port between the iluid chamber and the uid connection from the bore to the reservoir and a position blocking such fluid passage and a spring urging the piston into open position; and an electrical system for operating the pump and the control valve including a switch remote from the housing having a closed position for energizing'the pump and the control valve to move the piston 'thereof` into blocking position and the remote switch having an open n position for de-energizing the pump and control valve to release the piston for movement by the valve spring into open position.

14. An expander tool comprising an elongated housing having a cylindrical chamber therein and a central bore concentrically extended endwardly from the chamber, a piston reciprocally mounted in the chamber, a piston rod connected to the piston and extended therefrom into the bore, laterally expandable workpiece engaging means connected externally to the housing, a connecting rod extended into the bore in abutting relation with the piston rod, means interconnecting the laterally expandable means and the connecting rod for controlled expansion and collapse of the expandable means in response to movement of the connecting rod, means yieldably urging the expandable means into collapsed position, a fluid reservoir, a pump having an outlet connected to the chamber and an inlet connected to the reservoir, a lluid control valve interconnecting the chamber and the reservoir having an open position permitting fluid flow from the chamber to the reservoir and a closed position blocking fluid llow therethrough, said valve being resiliently urged into open position, electromagnetic means operable upon c nergization to urge the valve into closed position, and electrical control means for correspondingly energizing and de-energizing the pump and the electromagnetic means.

l5. In a remotely controlled expander tool for boreholes and the like, the combination of a substantially fluid tight housing having opposite ends, means connected to the housing for positioning the housing in a borehole, a plurality of segmented arms pivotally attached to an end portion of the housing and extended longitudinally of the housing, said arms being laterally spreadable into engagement with the Walls of a borehole and retractable therefrom, an hydraulic ram mounted in the housing having a controlling connection to the arms, a reservoir for hydraulic uid within the housing, an electrically energized pump within the housing connected to the reservoir, electrically controlled means within the housing having fluid connection to the pump, to the ram, and the reservoir, said electrically controlled means having an energized condition in which fluid passage therethrough from the pump to the ram is provided and a fle-energized condition in which fluid passage from the ram to the reservoir in by-pass relation to the pump is provided, and an electrical system connected to the pump and to the electrically controlled means adapted concurrently to energize and to deenergize the same by connection and dis-connection to a source of electrical energy remote from the housing.

(References on following page) References Cited in the le of this patent UNITED STATES PATENTS Ferren June 2, 1874 Stewart Jan. 20, 1914 Gould Feb. 19, 1924 Bierce Oct. 4, 1927 Steiner Feb. 18, 1930 Langstaff July 1, 1930 Wagner June 26, 1934 10 14 Burt Sept. 3, 1935 Carey Jan. 12, 1937 Danner Aug. 17, 1943 Fisher Apr. 4, 1944 Merten Sept. 26, 1944 Kirby Mar. 27, 1951 Audemar May 20, 1952 Koch June 30, 1953

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