US2672200A - Well bridge - Google Patents

Description

March 16, 1954 PATTERSON 2,672,200

WELL BRIDGE 3 Sheets-Sheet 1 Filed March 1, 1950 INVENTOIIQ.

22247122035. PQZZEJ'EUIZ T. G. PATTERSON March 16, 1954 WELL BRIDGE 3 Sheets-Sheet 2 INVEN TOR. 1 15012205151 Fazzez's'mz 2 H15 {FEE/V Filed March 1, 1950 March 16, 1954 T. G. PATTERSON WELL BRIDGE 5 Sheets-Sheet 5 Filed March 1, 1950 INVENTOR. 51 5.222.425 flin [52:50.22 2 H15 EFF/W Patented Mar. 16, 1954 UNITED STATES PATENT OFFICE "WELL BRIDGE ThomasG. Patterson, Graham, Tex.

Application March 1, 1950, Serial No. 146,975

13 Claims. 1

This invention relates; to improvements in well bridges and more particularly to well bridges for positioning within the bore hole or casing of a well, preparatory to the placing or in combination with the placing of an explosive charge in the well to be detonated.

Various well bridges have been proposed heretofore, and while some of these have been reasonably satisfactory under certain conditions, they were unsatisfactory under other conditions.

The present invention has been so designed as to meet all normal conditions confronting the placing of a bridge in the bore hole of a well, and furthermore, the invention meets certain other conditions and requirements not found in bridges in use heretofore.

An object of this invention is to provide a well shooting bridge that is easy to set, positive in action, andsafe to set and to remove should it be prematurely located in the bore, hole of the well. i

Another object of this invention is to providea well shooting bridge that may be seated either in theopen bore hole of a well, or within the casing of the well.

A still further object of this invention is to provide a bridge which may be utilized to carry an explosive charge below thebridge while the bridge is being lowered into place.

Still another object of the invention is to pro- 1 vide a well shooting bridge'which has an uninipededcentral opening through a portion thereof vto permit the seating of an explosive charge within the interior or the bridge, such as a time bomb.

A still .further object of the invention is to provide a well shooting bridge having an expand- .able member secured thereto and surrounding said bridge to enable the placing of gravel or other medium around thelbridge so as to properly direct the force of the explosive when detonated. Yet another object ofthe invention is to proelement that surrounds the bridge, and which i releasable band hasno projections thereon which extend beyond the outer periphery of said flexible element.

With til?above.ob-jects-in-mind and others that. i l-be ome pparent as the descripti n-F ceeds, the invention will best be understood from the following description, taken in conjunction with the accompanying drawings, which make up a specification of the same, in which:

Fig. l is a vertical sectional view through -;a bore hole of a well, showing the bridge in seated relation, with parts shown in elevation and with parts broken away and shortened, and shown in phantom outline, to bring out the details of construction;

Fig. 2 is a fragmentary view of the lower portion of the well shooting bridge, showing the gripping dogs in retracted position;

Fig. 3 is a fragmentary view of the lower portion of the well shooting bridge, showing the surrounding flexible element or umbrella in closed position, and showing the retaining U-pin in position to retain the umbrella in retracted position;

Fig. 4 is a fragmentary view of the upper portion of the well shooting bridge, taken substantially at right angles to Fig. 2;

Fig. 5 is a sectional view taken on the line 5-5 of Fig. 4, looking in the direction indicated by the arrows;

Fig. 6 is a sectional view taken on the line 66 of Fig. 4, looking in the direction indicated by the arrows;

Fig. 7 is a sectional view taken on the line 1-1 of Fig. 4, looking inthe direction indicated by the arrows;

Fig. 8 is a perspective view of the flexible retaining band to retain the umbrella or flexible element in closed condition during the lowering of the bridge into the well;

Fig. 9 is an elevational view of a modified form of the tool, with parts broken away and shown in section, of the tool in suspended position;

Fig. 10 is a sectional view of the tool taken on the line l0--l0 of Fig. 9, looking in the direction indicated by the arrows;

Fig. 11 is a fragmentary view of the lower portion of the tool, showing a further modification of the tool and Showing the umbrella in closed position; with parts broken away and shown in section to bring out the details of construction;

Fig. 12 is a fragmentary view of the tool, similar to Fig. 11, but showing the umbrella in released and open position, and with parts broken away and shown in section to bring out the details of construction; and

Fig. 13 is a fragmentary sectional view of the upper portion of the upper tubular body, showing an attaching hook in elevation attached to the bail thereof.

With more detailed reference to the drawing, the numeral I designates the bore hole of a well in which a casing 2 may be positioned as desired. A bridge structure, generally designated at 3, is adapted to be lowered into the bore hole 5 by means of a line 4, which line 4 has release hook mechanism ,5 ,on the lower end thereof adapted to en age a bail 6. While a conventional form of hook or release mechanism is shown, any desired form of the same may be used.

The bail 6 is pivotally mounted at l, and may hinge to one side released, as shown in dashed outline in Fig. 4.

In lowering the bridge into the bore hole of the well, the tubular element 8 to which the bail 6 is pivoted, will support a pair of side bars 9,, which side bars 9 are slidably fitted over a squared key member if), and the side bars 8 are held in' place by a disc or washer which is welded to the key member 10, as is best illustrated in Figs. 2 and 5. When in suspended condition, the upper end of slot 12 rests on the upper end of key member Ill. A pair of elliptical arms 13 protrude downwardly along the inner faces of side bars 9, and are fitted within a retain ng lug [5, as will best be seen in Figs. 4 and 6, so upon relative movement of the tubular member 8 and the side members 9, the lug member it will cause outward and inward movement of the elliptical arms 13, which arms I3 carry wall engaging dogs IS. The wall engaging dogs it are pivotally mounted on modified elliptical arms l3, so that the dogs IG may either grip the inner wallet the well casing with teeth ll, or the points is may project outward as indicated in dashed outline l5 to position the arms outward, and at the same 4 time cause the spring to yieldably retain the upper end of the dog, so as to cause the points 1'8 to project outwardly almost at right angles with respect to the sidebars 9.

It is preferably to have the points It of barbed construction, so as to dig into the side walls of the bore hole of the well. The side bars '9 -ex tend downwardly and have slots 29 near the respective lower ends thereof, in which is fitted a squared key member, which key 21 has a disc or washer 22 secured to the outer face thereof, so .as to retain the side bars 9 intermediate the disc 22 and the bottom -cylindrical member 23. The bottom cylinder member 23 has a pair of modified elliptical arms 24 hinged at 25 to the lower tubular member 23. The modified elliptical arms 24 pass upward along and in contact relation to side bars 9, and through a staple 26 in closed relation, so upon relative movement of lower tubular member 23 with respect to side arms 9, the arms 24 will be caused to move outward and downward relative to lower tubular member 23, as shown in Figs. 1 and 2.

As the side bar 9 moves upward with respect to the lower tubular member 23, the lower bar of staple 28 will contact the under surface of the modified elliptical arms 24 tocause the .arms to withdraw into the positionas shown in Fig. 2. The modified ellipticalarms 24 each-carry a wall engaging .member 21 which may be in the form of a toothed slip member having upwardly pointing teeth inversely disposed with respect to the teeth H of the dog l6.

In this manner the teeth 28 of slip 2! will be caused to engage the wall of the well or of the casing upon upward movement of the lower tubular member 23 relative to side bars 9.

The lower tubular member extends downward to form a preferably conical point .29, which is adapted to receive an explosive charge container, or if desired, the explosive may be placed directly therein. A flexible element, such as a cord or cable 30, may be provided and is adapted to be secured to or above release element 5, to extend downwardly within the interior of upper tubular member 23, to a point near the top of a flexible umbrella element 3!, to engage a U-shaped pin 32. The U-shaped pin 32 projects through loops 33 formed on the inner ends of flexible bar member 32. The bar 34 protrudes through an openingwithin the umbrella 31 and "the lower tubular member 123, so as .to protect the loops '33 and U-shaped pin 32 against mislocation because of encountering obstructions within the bore hole of the well.

The cord or cable 30 has suflicient slack therein so as to not disengage the U -shaped element 32, until after the release mechanism '5 has released the bridge, generally designated by the numeral 3, at which time the cord 39 will cause the U-shaped pin 32 to be withdrawn "from loops 23, which will permit the bar '34 to open and cause a spreading action of umbrella 31.

The purpose of the umbrella 3| is to form an obstruction in the well which will enable gravel or other material to be :packedia'round the bridge to retain debris from dropping downward into the well, during the fixingor placing of the bridge preparatory to shooting the well with nitroglycerin, dynamite, or other explosive.

A hook 35 is attached to the lower end of a conical point'29 and has a guard bar 36 attached to the conical :point 29 for cooperation with the hook 35 to make possible the attachment "of an explosive container 31 by bail 6a, as will be seen from Fig. 1. In this manner, one or more shot shells maybe connected to the bridge by a bail which connects to the hook 35,'the manner of attachment being shown in Fig. 9. A time bomb or a-speeial detonating charge may be carried within the bridge, or seated therein after the bridge has been run in place, as indicated in Fig. 1.

The umbrella 31 preferably has stays 38, which are hinged at 39 .to the lower end of lower tubular member 23. In this manner the umbrella, generally designated "at 3|, will spread out to close the comparatively small bore hole, or'it may extend out to close a comparatively large bore hole.

Operation 'In the operation of the device, thebridge, generally designated at 3, is attached to a cable, or to a steel measuring line by means of a hook or unlatching mechanism 5, and is lowered into the well to the proper depth. In event the lower end of the bridge strikes an obstruction which retards the downward descent thereof and allows the slips 2-1 to engage. The device may then be raised and again lowered until it reaches the proper depth. Whereupon, the container 31 will engage the bridge or the bottom of the well, and the point 29 of the lower tubular member 23 will seat within the top of the charge container, which will cause the upper tubular member "8 to slide downward Withresp'ect to the side-bars '9.- In so doing, the side bars'will slide downward with re-- speot to the lower tubular member 23. As upper tubular member 8 slides downward with respect to the side bars 9, the downwardly extending modified elliptical arms i3 will be caused to move outward, either to cause teeth I! to engage the inner walls of the casing 2, or the dogs l6 to project outward into the open bore hole, if the tool is being used in .an uncased well. The points l8, in this event, will engage within the strata. After the dogs 16 have moved into position, the slide bars 9 will continue to slide downward with respect to lower tubular member 23, and the upper bar of the staple will cause a spreading action of the modified elliptical arms 24 so as to cause engagement of the teeth 28, either with the inner wall of the casing 2, or with the wall of the bore hole, if the well is uncased.

The teeth 28 of the slips 2'! are upwardly seating, whereas the teeth I l of the dog 1 5 are down wardly seating. In this manner the unit is restrained against upward movement exerted by pressure exerted below tubular member 23 and is constrained against downward movement by the. downwardly seating teeth I! or the points id of the dog.

After the device is securely seated and secured against upward or downward movement, the lowering line 4 is detached from the bail E by a hook or unlatching member 5, which usually unlatches after a required number of pulls are given to the line 4, then the line 4 is moved up. After the line 4 moved up and the cord or cable 36 which is attached to U-container 32, is slipped out of loops 33, the cord or cable 38, which is attached to the cable 4 of the U-container 32, permits a plurality of torsion spring elements S, one

for each stay, to swing the respective stays 33 outward. to cause a flexible element or umbrella to close the bore hole of the well to prevent the downward movement of gravel therein, as this umbrella serves as a container to receive a gravel pack, preparatory to the detonating of an explosive charge.

Although it has been pointed out that the device is used in connection with the explosive charge containers 31, it may also be used without the umbrella, for safety protection against gun after the detonation has taken place. When used with a gun perforator, the gun perforator may be lowered into the exact place desired, and the device operated to thoroughly secure the same in place in the well to prevent either upward or downward movement of the gun perforator, in event an unexpected flow of oil or gas is en countered. The tool may also be used in connection with the treatment of the oil strata by utilizing the effect of the seating of the tool carrying the umbrella, within the bore of the well, so that gravel or other sealing material may be placed in and above the umbrella 38 which will prevent an upward surge of pressure due to the reaction of steam or chemicals which may be used in the treatment of the strata, thereby holding the pressure below the umbrella to cause penetration of the chemical under pressure, into the earth formation in the bore hole-of the well.

The forms. of the invention, asillustrated-in Figs. '9 and .10, show substantially the same .body

and slip structure, as. described above and Show in Figs. 1 to 8, but a different release mesh-a nismis provided for the umbrella. This form of the invention, is provided with an upper tubular body 5| and a lower tubular body 52, havin rea spective slip members 53 and 54, respectively 0p eratively comiected thereto. The side bars 55, in which the respective slots 56 and 5! are formed. and which slots permit sliding action of key members 58 and 59 respectively. The side bars extend downward below slot 51 and is secured to a ring 60, which ring is spaced outward from body 52 so as to form an engaging member for re-entrant hook portions 6| of stays 62. The stays 62 are secured to the canvas or fibrous element 63 by clips 64 riveted or otherwise se cured to the canvas 63. The lower end of the stays 62 may be hingeably connected to body 52. in the same-manner as shown in Fig. 1. A torsion spring may be utilized, which is similar to the torsion spring S, shown in Fig. 1, to cause an outward movement of stays 62, when the dcvice is in released position in the well.

The ring is somewhat conical or spherical in shape, with upwardly and outwardly diverging walls to inter-engage beneath re-entrant hook portion 6| of stays 62. The stays 62 are so formed that the points 65 are in close prox imity to the outer circumference of the lower body member 52, which prevents engagement with obstructions on the walls of the well, should it become necessary to lift the device upward to dislodge from an obstruction within the well.

With the bodies 5! and 52 in suspended relation, the side bars 55 will cause the ring 60 to move upward under reentrant hook portions Bl, so as to support lower tubular member 52, and also to keep the umbrella, generally designated by the letter U, in collapsed condition during the descent of the tool into the well, and until it is desired to release the umbrella for spread ing outward in the bore of the well.

Upon downward movement of the device an exposive charge 66 may be suspended by hook 6.! until the explosive container 66 seats on the bottom of the well or on a bridge, at which time the lower body portion 52 will seat on the explosive container 66, which will cause the umbrella U to open, so that gravel or other hole closing material may be lowered or dumped thereinto, but not allowed to pass there-beyond. Thus the umbrella holds the gravel or other material as it is filled into the bore hole of the well, so that it is held in the. desired place to direct the force of the explosive charge downward and outward.

The. form of the invention as shown in Figs. 11 and 12, is somewhat similar to the form'shown in Figs. 9 and 10, except that the-lower body portion 12 provides for the side bars15 to extenddownward and attach to an annular ring that has upwardly and outwardly diverging sides, so when engaged with the stays 82, the umbrella will be held inward until the lower portion of body l2 seats upon an obstruction such as a bridge or the bottom of the well. The ring 80 will then move downward permitting-the stays, which are preferably of resilient construction, to spring outward, as indicated in Fig. 12. In the form of the invention as shown in Figs. 11 and 12, the umbrella may be collapsed upon upward movement of the side bars 15, and the compressor ring 39 attached thereto.

1 Other-features Ofi17hiS"fOrm. or thev invention. asslshownin Fleece to; 12, inclusive; have been treated in the form of the invention shown in Figs. 1 to 8, and it is believed that these features have been described in such manner as to be clearly understood, both as to construction and manner of operation, as not to require further explanation, and that they have been sufficiently covered in the detailed description of the form of the invention as shown in Figs. 1 to 8.

Having thus clearly shown and described the invention, what is claimed as new and desired to secure by Letters Patent is:

l. A bridge for use in a well comprising a pair of longitudinally spaced bodies, a bar having projections thereon which bar slidably interconnects said spaced bodies, pairs of arms each arm of which is pivotally connected at one end to each of said bodies, each of said arms having its opposite end pivotally connected to a slip member, each pair of arms being engageable with said respective projections on said bar so upon relative movement between said bodies and said bar, said projections will cause relative movement between said slip members and said bodies so as to cause ngagement of said slip members with the wall of said well upon movement of said end of said stays, and holding means for said inverted umbrella on said bar, means connecting with said holding means on said bar to disengage said inverted umbrella so as to permit said umbrella to open by resilient action of the stays thereof so said umbrella will form a receptacle intermediate the walls of said well and the lowermost of said bodies.

2., A bridge to be lowered into a well by means of a lowering line which bridg comprises longitudinally spaced upper and lower tubular bodies, means on the upper of said bodies for attaching a lowering line, bars slidably interconnecting said spaced tubular bodies, a pair of arms hingeably connected to each of said bodies, each of said arms having a slip member swing-ably connected thereto, pairs of guide members on each of said bars and each pair of said guide members interengageable with a pair or said arms, each pair of slip members being adapted to move laterally upon relative movement between said bodies and said bars, an umbrella element comprising a sheet of flexible material and ribs which ribs are pivotally connected to said lowermost tubular body near the lower end thereof for outward swinging movement of the upper end of said ribs, spring means for urging the upper ends of said ribs outward and means for interconnecting said ribs and said flexible sheet of material for unitary movement thereof to form a receptacle between said lower-most tubular .nected to the uppermost of said bodies for moving one of said bodies relative to the other of said bodies and for lowering said bridge into said well and for removing it therefrom, pairs of slip members, and linkage means for pivotally connecting a pair of said slip members to each of said bodies, said projections on said bar slidably engaging said linkage, each of said pairs of slip members being movable outward successively into contact relation with the wall of said well by the relative movement of the upper of said bodies downwardly toward the other of said bodies on said bar when the movement of the lower-most of said bodies is arrested, and each of said pairs of slip members being movable inward successively by the movement of the upper of said bodies upwardly away from the other of said bodies on said bar.

4. A retrievable bridge for wells comprising a pair of tubular bodies spaced from each other longitudinally and axially aligned, a pair of bars interconnecting said longitudinaly spaced tubular bodies which bars have projections thereon, which bars are slidable relative to each of said bodies, means connected to the upper-most of said bodies for moving said bodies relative to each other and for lowering said bridge into said well and for removing it therefrom, pairs of slip members, and linkage means for pivotally connecting a pair of said slip members to each of said bodies and passing outwardly in contact relation with said projections, each of said pairs of slip members being separably movable outwardly into contact relation with the wall of said well by the respective movement of one of said bodies toward the other of said bodies on said bars, and each of said pairs of slip members being separably movable inward by the relative movement of one of said bodies away from the other of said bodies on said bar.

5. A retrievable bridge for wells comprising a pair of tubular bodies spaced from each other longitudinally, a pair of bars interconnecting said longitudinally spaced bodies, which bars are slidable relative to each of said bodies, means connected to one of said bodies for moving one of said bodies relative to the other of said bodies and for lowering said bridge into said well and removing it therefrom, slip members, pairs of arms hingeably connected to each of said tubular bodies and each of said arms having one of said slip members pivotally attached thereto near the outer end thereof, means slidably connecting each of said bars with each of said arms so upon relative movement between said bars and said arms in one direction, said slip members will be caused to move outward, and upon movement of said bars with respect to said arms in the opposite direction said slip members will be caused to move inward.

6. A bridge for lowering into a well by means of a pull line, which bridge comprises a pair of longitudinally spaced tubular bodies, a pair of bars slidably interconnecting said spaced tubular bodies, a pair of modified elliptical arms hingeably connected to the lower end of the uppermost of said longitudinally spaced, tubular bodies and another pair of modified elliptical arms hingeably connected to the upper end of the lower-most of said bodies, slip members, each of said arms carrying one of said slip members, means forming a sliding connection between each of said arms and said pair of bars so as to spread said arms outward upon the relative downward movement of said bar with respect to the lowermost of said bodies and by downward movement of the upper-most of said bodies relative to said bar, and; means connected to the upper-most :of "said tubuia'r: bodies iior lowering said bridge into said: well and fior'm'oving said bodies and said bar relative to each other.

l. A- 'retrievaiblebridge for wells: comprising a pair of tubular bodies spaced from each other longitudinally, a bar interconnecting said longitudinally spaced bodies and having projections thereon, which bar is slidable relative to each of said bodies:,-moans connected to the upper-most of said bodies :for'rmoving "said. bodies relative to each-other and for: lowering. said bridge into "said Well removing it therefrom, pairs or slip members, and linkage means for piyotally "conmeeting 'apatr ot said clip members to" each of said bodies-which linkage meanspass outward in contact relation with-said projections; ea-ch pair 'of :said slipmembers being movable outward :sucoe'ssi vely into contact relation with the wall of said well by relative inovtment of. the upper most of said bodies toward the other of said bodies on said bar when the movement of the lower most of said bodies is arrested, and each of said pairs of slip members being movable inward by the movement of theuppermost of said bodies away from the other of said bodies on said bar.

8. A bridge for wells which bridge is adapted toi'be set by a lowering line, said bridge comprisa pair of longitudinally spaced bodies, a bar slidably "interconnecting said bodies and having projections thereon, pairs of slip members, linkage means hingeably connecting a pair of said slips with each of said bodies, said projections on said bar slidably interengaging said linkage, each pair of said slips being movable outward for engagement with the wall of said well by relative movement between said bodies and said bar in one direction and inwardly out of engagement with the wall of said well when moved in the opposite direction, the lower-most of said bodies having resilient stays secured near the lower end thereof which stays extend upwardly and outwardly when in open position, a covering surrounding said lower-most body and secured thereto near the lower end thereof and to said stays to form an inverted umbrella, a ring surrounding said lower-most body near the upper end thereof and interengaging said stays when in one position to hold said umbrella in collapsed condition, means interconnecting said lowering line and said ring for releasing saidring from said stays, and a releasable hook means on said lowering line connected to the upper-most of said bodies for moving said bridge in said .well.

9. A bridge for wells which bridge is adapted to be set by a lowering line, said bridge comprising a pair of longitudinally spaced bodies, a bar slidably interconnecting said bodies and having projections thereon, pairs of slip members, linkage means hingeably connecting a pair of slips with each of said bodies, said projections on said bar slidably interengaging said linkage, each pair of said slips being movable outward for engagement with the wall of said well by relative movement between said bodies and said bar in one direction and inwardly out of engagement with the wall of said well when moved in the opposite direction, the lower-most of said bodies having resilient stays secured near the lower end thereof which stays extend upwardly and outwardly when in open position, a covering surrounding said lower-most body and secured thereto near the lower end thereof and to said stays to form an inverted umbrella, a re-entrant hook on the upper end of each of said stays, a ring iii) surroundingsa-id lower-most body near the upper end thereof and attached to said slidable bar and movable therewith, said ring: being in engagement with said re-entrant hooks when in. its uppermost position, and being disengaged .irom said i e-entrant books when in its lowermost position so as to release said umbrella stays and said :umbrella, means interconnecting with said lowering line and with said ring for releasing sari-during from'. said stays, and a releasable .hook means on said lower-ing line connected to 'said upper-most of saidbodies for moving said bridge in said well,

1-0. (A bridge for wells which. bridge is adapted to be set by a lowering line, said bridge comprising a. pair of longitudinally spaced bodies, a bar slidably interconnecting said bodies and having protections thereon, pairs of slip members, linkage means hi-ngeably connecting .a pair of said slips with each of said bodies, said projections on said bar slidably interengaging said linkage, each pair of said slips being movable outward for engagement with the wall of said well by relative movement between said bodies and said bar in one direction and inwardly out of engagement with the wall of said well when moved in the opposite direction, the lower-most of :said bodies having. resilientstays secured near the lower 'end thereof which stays extend upwardly and outwardly when .in open position, a covering :surroundingsaidllower-most body and securedthere- .to near the lower end thereof and to said stays to form an inverted umbrella, a slit formed in said umbrella near the lower-most part thereof which slit receives said slidable bar therethrough, a ring having its inner side diverging upwardly and outwardly and said ring being connected to said slidable bar and positioned below said umbrella and said stays so said ring will wedgingly compress said stays in collapsed condition when said ring is in its upper position, but which ring will permit outward spreading of said umbrella and said stays when said ring is in its lower position, and releasable hook means on said lowering line connected to the upper-most of said bodies for moving said bridge in said well.

11. A bridge to be lowered into a well by means of a lowering line, said bridge comprising longitudinally spaced upper and lower tubular bodies, means on the upper of said bodies for attaching said lowering line, a pair of bars slidably interconnecting said spaced tubular bodies and having projections thereon, pairs of slip members, linkage means hingeably connecting a pair of said slip members with each of said bodies, said projections on said bars slidably interengaging said linkage, each pair of said slip members being movable outward for engagement with the wall of said well by relative movement between said tubular bodies toward each other, said lowermost tubular body being closed at its lower end to form a seat, an expansible umbrella member secured to the lower end of said lower-most tubular body and extending upwardly therearound, means coupled with said lowering line. for releasing the upper end of said umbrella member so said umbrella member will open outwardly at its upper end to form a receptacle between said lower-most tubular body and the wall of said well.

12. A bridge to be lowered into a well by means of a lowering line, which bridge comprises longitudinally spaced, upper and lower tubular bodies, means on the upper-most of said bodies for attaching a lowering line, bars slidably interconnecting said longitudinally spaced tubular 1 l bodies and having projections thereon, pairs of slip members, linkage means hingeably connecting a pair of said slips with each of said bodies, said projections on said bars slidably interconnecting said linkage, each pair of said slip members being movable for engagement with the wall of said Well by relative movement between said bodies toward each other on said bars, said lowermost tubular body being closed at its lower end to form a seat, an umbrella element comprising a sheet of flexible material and ribs, which ribs are pivotally secured to the lower end of said lower-most tubular body and extending upward therearound, a band surrounding the upper portion of said ribs, and means for coupling said band to said lowering line for selectively releasing said band from said ribs so the upper end of said umbrella element will expand outwardly to form a receptacle between said lower-most tubular body and the wall of said well.

13. A bridge to be lowered into a well by means of a lowering line, which bridge comprises longitudinally spaced, upper and lower tubular bodies, means on the upper-most of said bodies for attaching a lowering line thereto, a pair of bars slldably interconnecting said longitudinally spaced, tubular bodies and having projections thereon, pairs of slip members, linkage means hingeably connecting a pair of said slips with each of said bodies, said projections on said bars slidably interengaging said linkage, each pair of said slip members being movable for engagement 12 with the wall of said Well by relative movement between said bodies toward each other on said pair of bars, said lower-most tubular body being closed at its lower end to form a seat, an umbrella element comprising a sheet of flexible material and ribs, which ribs are pivotally secured near the lower end of said lower-most tubular body for outward swinging movement of the upper ends of said ribs and flexible sheet material, a flexible band surrounding the upper portion on said ribs, a loop formed on each end of said band, which loops protrude into said lower-most tubular body, a U-shaped connector attachably fitted within said loops for normally retaining said band in a fixed relation around said ribs, and means connected to said U-shaped connector and said lowering line for selectively releasing said band from said ribs to cause the spreading of said umbrella element so as to form a receptacle between said lower-most tubular body and the wall of said well.

THOMAS G. PATTERSON.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,497,629 Baker June 10, 1924 2,141,030 Clark Dec. 20, 1938 2,225,143 Baker et a1. Dec. 17, 1940 2,253,224 Bleakley Aug. 19, 1941

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