US3222088A

US3222088A - Wellhead connector with diagonally directed latches

Info

Publication number: US3222088A
Application number: US148492A
Authority: US
Inventors: John A Haeber
Original assignee: Shell Oil Co
Current assignee: Shell USA Inc
Priority date: 1961-10-30
Filing date: 1961-10-30
Publication date: 1965-12-07
Anticipated expiration: 1982-12-07

Description

Dec. 7, 1965 J. A. HAEBER 3,222,088

WELLHEAD CONNECTOR WITH DIAGONALLY DIRECTED LATCHES Filed Oct. 30. 1961 4 Sheets-Sheet 1 Fl G. l

INVENTOR:

J. A. HAEBER IS AGENT Dec. 7, 1965 J. A. HAEBER 3,222,088

WELLHEAD CONNECTOR WITH DIAGONALLY DIRECTED LATCHES BY: HJM Q (1% HIS AGENT Dec. 7, 1965 J. A. HAEBER 3,

WELLHEAD CONNECTOR WITH DIAGONALLY DIRECTED LATCHES Filed Oct. 50, 1961 4 Sheets-Sheet 4 FIG. IO

FIG. 9

INVENTORI J. A. HAEBER BY: .Hju c zg AHIS AGENT United States Patent 3,222,088 WELLHEAD CONNECTOR WITH DIAGONALLY DIRECTED LATCH-IE8 John A. Haeber, Houston, Tex, assig-nor to Shell Oil Company, New York, N.Y., a corporation of Delaware Filed Oct. 30, 1961, Ser. No. 148,492 2 Claims. (Cl. 285-18) This invention relates to apparatus for use in offshore wells and pertains more particularly to a wellhead apparatus adapted to be securely locked on a well casinghead position under water. The present invention is especially concerned with apparatus for connecting a wellhead component, such for example as a blowout preventer, to a vertically-extending wellhead component in a securely locked and fluid tight manner so that the wellhead component could not be accidentally separated from the vertically-extending well member.

In an attempt to locate new oil fields an increasing amount of well drilling has been conducted at offshore locations, such for example, as off the coast of Louisiana, Texas, and California. As a general rule, the strings of casing in a well together with the tubing string or strings extend to a point above the surface of the water where they are closed in the conventional manner that is used on land wells, with a conventional wellhead assembly being attached to the top of the casing. Attempts have been recently made to provide methods and apparatus for drilling and completing a well wherein both the well casing head and subsequently the wellhead assembly and casing closure device are located underwater at a depth sufficient to allow ships to pass over them. Preferably, the casinghead and wellhead closure assemblies are located close to the ocean floor. In order to install equipment of this type underwater at depths greater than the shallow depth at which a diver can easily operate, it has been necessary to design entirely new equipment for this purpose. Thus, when drilling and completing an oil well or a gas well at an offshore location, the well casinghead may have attached to it pieces of equipment by means of the apparatus of the present invention.

It is, therefore, a primary object to the present invention to provide apparatus for connecting a wellhead component to an underwater wellhead assembly while operating the apparatus from the remote location.

It is another object to the present invention to provide a wellhead component, such as a blowout preventer with a connector device, so that after the blowout preventer is lowered and seated on an underwater well casinghead it can be securely locked and sealed thereto in a fluid tight manner with the sealing and locking operations carried out from a remote location.

A further object to the present invention is to provide a remotely-operable connector apparatus adapted to lock automatically on an underwater wellhead and pack off Lhe annulus between the connector apparatus and the wellead.

Another object to the present invention is to provide a remotely-controlled hydraulically-operated connector device and sealing apparatus for holding a wellhead component on a wellhead against pressures which might be encountered therein in any time, even in the event that the hydraulic pressure lines to said apparatus should break, or otherwise become inoperative.

A further object of the present invention is to provide a wellhead connector device and sealing apparatus which may be readily unlocked from an underwater wellhead and raised to an operational base of the surface, such for example, as to a drilling barge or platform.

Another object to the present invention is to provide a wellhead connector adapted to seat on an underwater wellhead and be connected to the inside or outside thereof, depending on the particular type of operation to be conducted.

A further object of the present invention is to provide a wellhead connector device and sealing apparatus which may be automatically locked to a wellhead assembly wherein any wellhead pressure is utilized to maintain the connector device in a locked position on the wellhead assembly.

Still another object to the present invention is to pro vide a wellhead connector and sealing device attachable to a wellhead component and being provided with locking means arranged in a manner to block disengagement of the blocking means when forces are applied to separate the connector device and the wellhead component.

These and other objects of this invention will be understood from the following description taken with reference to the drawing, wherein:

FIGURE 1 is a diagrammatic view illustrating a floating drilling barge positioned on the surface of the ocean in which a blowout preventer together with the connector device of the present invention is being lowered to the top of the well casing positioned on the ocean floor;

FIGURES 2, 3 and 4 are views taken in longitudinal cross section of one-half of one form of a wellhead connector of the present invention, the wellhead connector being illustrated in its running position, et position, and releasing position, respectively, in the three figures;

FIGURES 5 and 6 are views taken in longitudinal cross section of one-half of another form of a wellhead connector of the present invention shown in its unlocked and locked positions respectively;

FIGURE 7 is a fragmental longitudinal view taken in cross section of a modification of the latching device of the connector illustrated in FIGURE 6;

FIGURE 8 is a fragmental view taken in longitudinal cross section of a modification of a piston of the connector shown in FIGURE 6;

FIGURE 9 is a longitudinal view taken in cross section of one-half of another form of the wellhead connector of the present invention; and,

FIGURE 10 is a fragmental view taken in longitudinal cross section of another piston arrangement for actuating the locking element of the connector device to the present invention.

Referring to FIGURE 1 of the drawing, a drilling barge 11, of any suitable floatable type is illustrated as floating on the surface of the water 12 and fixedly positioned over a preselected drilling location by being anchored to the ocean floor 13 by suitable anchors (not shown). Equipment of this type may be used when carrying on well drilling operations in water depths varying from about to 1500 feet or more. The drilling barge is equipped with a suitable derrick 16 and a rotary table 17 as well as other auxiliary equipment needed during the drilling of the well. The derrick 16 is positioned over a drilling slot or well 18 which extends vertically through the barge in a conventional manner. When using the equipment of the present invention the slot of the barge 11 may be either centrally located or extend in from one edge. However, drilling operations may be carried out over the side of the barge without the use of a slot. Additionally, it is to be understood that the equipment of the present invention may be also used while drilling a well from any suitable operational base positioned above the surface of the water, such for example, as from a drilling barge having feet extending to the ocean floor, or from a platform permanently positioned on the ocean floor.

A typical underwater wellhead structure is illustrated in FIGURE 1 as comprising a base member 21 which is positioned on the ocean floor 13 and is fixedly secured to a conductor pipe or a large-diameter well casing 22 which extends down into a well, which has been previously drilled, and is preferably cemented therein. Thus, the base structure 21 is rigidly secured to the ocean floor in order to support two or more vertically-extending guide columns 23 and 24 adapted to receive and guide therein

guide arms

25 and 26 which are arranged to slide along vertically-extending guide cables 27 and 23. The lower ends of the guide cables27 and 28 are anchored to the base structure 21 within the guide columns 23 and 24 while extending upwardly through the water to the drilling barge 11 where they are preferably secured to constant tension hoists 31 and 32.

Centrally positioned above the base plate 21 and fixedly secured thereto, or to the conductor pipe 22, is a well casinghead 33 which is provided with a latching shoulder 34, which may be in the form of one or more grooves, and extends preferably around the periphery of the easinghead. The wellhead is also shown as being provided with a cement circulation or kill line 36 which is connected preferably by means of a quick-disconnect coupling 37 to a flow control valve 38.

The

guide arms

25 and 26 are illustrated as being connected to a blowout preventer 40 which is rigidly flanged to a wellhead connector 41 of the present invention. In FIGURE 1 the wellhead connector 41 is shown as it is being lowered onto the top of the casinghead 33. The combined blowout preventer and

wellhead connector

40 and 41, respectively, are run into position on the top of the well by being lowered through the .water from the barge 11 by means of a pipe string 42, commonly known as a running string, the blowout preventer 40 being connected to the lower end of the running string 42 by means of a suitable coupling or connector 43 which may take the form of the wellhead connector 41. The coupling or connector 43 is provided with a pair of guide arms 25a and 26a. The valve 38, connector 41, blowout preventer 40, and connector 43 are all hydraulically operated and are provided with

hydraulic flow lines

44 and 45, 46 and 47, 48 and 49, 50 and 51, respectively. These flowlines, 44 through 51, extend upwardly from the wellhead equipment to the barge 11 where they are connected to a suitable source of pressure fluid.

Referring to FIGURE 2 of the drawing, the wellhead connector 41 of FIGURE 1 is shown as comprising a body member having upper and

lower portions

54 and 55, respectively, which are connected together in any suitable manner, as by screw threads 56. Preferably, the lower end of the body portion 55 is provided with an outwardly flaring skirt 62 which surrounds the bore 63 extending upwardly through the body member 5455. The upper body portion 54 has a bore 64 of reduced diameter, thus forming a seating shoulder 65 which is adapted to seat on a landing surface 66 (FIGURE 3) formed on the outside of a vertically-extending well member 67, preferably at the upper end thereof, as illustrated. The well member 67 is provided with a bore 68 therethrough. Formed on the outer surface of the vertically-extending well member 67 are one or

more shoulders

74, 74a and 74b which may take the form of grooves extending partially or all the way around the well member. The latching shoulders 74,.74a, and 74b formed on the well member 67 are positioned down from the top of the well member 67 a distance equal to the distance that a plurality of latching dogs 75, carried by the body member 54-55, are positioned from the seating shoulder 65 in the upper body portion 54.

In the description of the connectors of the present invention, it is to be understood that the connectors are annular in shape and symmetrical in construction so that it is considered suflicient to describe the actuation of a single latching dog 75 thereof while it is to be understood that the body member 54-55 is provided with a plurality of latching dogs arranged in a spaced relationship around the body member and are mounted for simultaneous actuation therein. For each dog 75 carried by the body member 5455, a vertically-extending recess 57 is provided in the body portion 55, each recess 57 being slightly wider than the latching dog 75 contained therein. The recesses 57 extend out of the housing portion 55 in a downward direction which is governed by the design angle of the upper and lower surfaces, 58 and 59, respectively, of the recess 57. While the angle of the diagonally-directed

surfaces

58 and 59 is illustrated as being substantially a 45 angle, it is to be understood that any suitable angle say from about 25 to 65 from the horizontal may be selected. Although the upper and lower faces 58 and 59 are illustrated as being at the same angle, the angle of the upper surface 58 is not critical and may be at an angle considerably less than that of the lower surface 59. The lower surface 59 forms the hearing surface governing the angle of movement for the latching dog 75 and forms a diagonally-directed blocking surface on the body member which blocks movement of the latching dog from engagement with the

shoulders

74, 74a and 74b when forces are applied to separate the body member 5455 from the well member 67.

The shoulder-engaging latching or locking dogs 75, carried by the body member 5455, are arranged for diagonal movement along the diagonally-directed or lower surfaces or walls 59 of the recesses 57 into and out of engagement with the latching

shoulders

74, 74a and 74b of the well member 67. Whatever angle is selected for the lower edge of the latching dog 75 or the diagonally-directed mating surface 59 of the recess 57, the contacting face of the dog 75 is preferably vertical and preferably grooved so as to form a plurality of seating and engaging

surfaces

60, 60a and 60b which are formed of a size and at an angle to engage

shoulders

74, 74a and 74b, respectively, of the well member 67. The angle of the engaging surface 60 on the dog 75 and in the angle of the cooperating shoulder 74 are preferably substantially equal to each other and to the diagonally-directed blocking surface 59,-forming the bottom wall of the recess 57 The latching dog 75 may be actuated in several ways. As illustrated in FIGURES 2, 3 and 4 of the drawing, the back or upwardly extending end of each dog 75 is operatively connected, as by any suitable means such as a hook or hinge element 76, to the lower end of a linkage member 77 which is preferably in a form of a springlike finger or collet which extends upwardly and is mounted for a limited vertical movement in the housing 5455. Fixedly secured to the top of each linkage member 77 and movable therewith is a shoulder element 80 which may be an individual element for each linkage member 77, or which may be in the form of an annular ring mounted for a limited axial movement Within the annular chamber 81 formed within the housing or body member 5455. A compression spring 82 is mounted above the shoulder 80 for normally urging at all times the shoulder element 80, linkage member 77 and latching dog 75 downwardly and outwardly into locking position.

Mounted adjacent the shoulder element 80 on the outside thereof within the annular chamber 81 is an annular piston 83 sealingly engaging the inner wall of the body member 5455 in a fluid tight manner at points 84, 85, and 86 where suitable sealing elements such as O-ring seals are employed. A pressure fluid may be supplied through

ports

87 and 88 to piston chamber 89 to drive the piston in opposite directions. If desired, only port 88 may be provided for raising the piston, and engaging shoulder 91 fixedly secured thereto on the inner surface thereof, for contacting and lift-ing the shoulder element 80 which is operatively connected through linkage member 77 to the latching dog 75. Since the latching dog 75 is spring-loaded at all times to its operative position, as illustrated in FIGURE 2, it is only necessary to provide actuating means for withdrawing latching dogs to their retracted position as shown in FIGURE 4. It will be seen that under normal conditions with no hydraulic pressure fluid being applied to the connector means, upon failure of pressure fluid supply the spring 82 would maintain a force on a shoulder 80 (FIGURE 3) and hence on the latching dog 75 to maintain the latching dog in a locked position in engagement with the

shoulders

74, 74a and 74b, thus preventing a relative axial separation of the body member 54-55 from the well member 67.

The body member 54-55 is provided with an annular packing element or seal 92 for sealing against the outer wall of the well member 67 (FIGURE 3) in a fluid tight manner. The annular seal 92 extends into the annular chamber 81 in which the piston 83 moves but is normally out of contact with the piston 83 when the piston is in its inoperative position, as shown in FIGURE 2. The upper end of the piston 83 is enlarged, as 93, and is provided with a camming face 94 which is designed to engage the periphery of the packing element 92 as the piston 83 in its enlarged portion 93 moved downwardly past the packing element 92 to a position shown in FIGURE 3. In this position the enlarged portion of the piston 93 maintains the packing element 92 in sealing engagement with the outer surface of the well member 67 Fluid passage means 95 of any suitable design are preferably provided through the wall of the body member 54- 55 from the bore 63 thereof at the point above the sealing element 92. In the present arrangement of the apparatus the fluid passage means is shown in the form of an annular space above the packing element 92 which is open at all times, even when the packing element 92 is in sealing engagement with the outside of the well member 67, as shown in FIGURE 3. It is to be understood that any suitable form of fluid ports could be drilled through the wall of the 'body member 54-55 from the interior bore 63 thereof at a point above the packing elements 92 to serve for the same purpose. The fluid passage means 95 permits well pressure to be applied to the enlarged portion 93 of the piston 83, thus maintaining the piston in its downward position, as shown in FIGURE 3, to keep the latching dogs 75 in engagement with the latching shoulders of the well member 67. Well pressure would pass up the bore 68 of the well member, across the landing surface 66 at the top thereof, down the outside of the well member 67, through the fluid passage means 95 above the sealing element 92 and thence into the top of the chamber 81 above the enlarged end 93 of the piston 83.

In latching the connector of the present invention to a well member which has been exposed to underwater conditions for some time, it may be that marine growth or other deposits partially fill the grooves forming the latching shoulders 74, 74a, and 74b on the outer face of the well member 67. In such a case it may happen that one or more of the latching dogs 75 is not completely seated in the grooves of the well member 67. Thus, in some arrangements of the connector of the present invention it is desirable to provide a downwardly extending end 96 on the piston 93 which is of a design and size that it fits tightly behind the locking dog 75 when the dog 75 is in its outermost position. If the dog is not in its outermost position, downward movement of the piston 82 causes the downwardly-extending end thereof to force the locking dog 75 outwardly all the way. If it is desired to determine whether the piston 83 has been forced to the bottom of its stroke through ressure being applied through port 87, the body member 54-55 may be provided with one or more electric switches 97 whose contact stem 98 is actuated by a spring-loaded rod 99 which extends upwardly through the body member 54-55 above the lower face 59 of the recess 57 and into the chamber 81. When the piston 83 is at the lower limit of its travel, its lower end 96 contacts the top of the spring-loaded rod 99 forcing it downwardly to close the switch 87 which would be indicated above the surface of the water on the operating barge. The electrical leads 100 from the switch 97 may 6 be secured to the outer surface of the connector 41 and run up along the side thereof.

In using the connector of the present invention, it would be run in its normal position (FIGURE 2) onto the top of the well member 67 (FIGURE 3), at which time the outer upper edge of the well member 67 would force the latching dog 75 of the connector upwardly into the recess 57 which is possible due to the diagonal sloping of the recesses 57 and the dog 75. The latching dog 75 would stay in the recess 57 until the body member 54-55 had been lowered so that its seating shoulder 65 was on the landing surface 66 of the well member, at which time the compression springs 82 and the linkage member 77 would force the dogs 75 to snap outwardly and latch in place on the grooves of the well member. In any attempt to cause relative axial separation of the body member 54-55 from the well member 67 while the latching dogs were in place (FIGURE 3), a force component would be exerted by the well member at the latching shoulders thereof directly across the latching dog 75 and be applied to the body member 54-55 through the diagonally-directed lower face 59 of the recess 57. Since this force component is exerted across the latching dog 75 substantially perpendicular to the diagonally-directed lower face 59 of the recess 57, or substantially perpendicular to the diagonal direction of movement of the latching dog 75, there is no tendency for this force component to unlatch the dogs 75 from the well member 67.

In FIGURES 5 and 6 a more simplified arrangement of the connector of the present invention is illustrated. The body member 154-155 is provided with an endplate 166 in which the recesses 157 are formed. The latching dogs positioned in the diagonally-directed recesses 157 are secured by suitable hinge means 176 to the lower end of a linkage member 177 which is rigidly connected to the lower end of a single-acting piston 183. The body member 154-155 is provided with a fluid port 188 through the wall thereof in communication with a piston chamber 189. A compression spring 182 is mounted above the piston 183 and serves to force the piston 183 and the latches 175 into their operating position, as shown in FIGURE 6, wherein the connector is shown as being positioned on a well member 167. The inner wall of the piston 183 is provided with a recess into which the sealing element 192 expands in its inoperable position. A fluid passage 195 is provided above the sealing element 192 for permitting well pressures to be applied above the piston 183 to aid the spring 182 in forcing the piston 183 downwardly and the locking dogs 175 outwardly when the present connector is latched onto a well member, as shown in FIGURE 6. In order for the piston in FIGURE 5 to achieve the position illustrated, it is necessary to apply a pressure fluid through port 188 into the chamber 189 to raise the piston 183 and the latching dogs 175 to their inoperative position. The lower end of the piston 183 is provided with a camming face 178 which is adapted to engage the upper end of the latching dog 175 and force it outwardly into its operative position, as shown in FIGURE 6.

In a modification of the connector of FIGURES 5 and 6, the piston 283 is shown in FIGURE 7 as being provided at its lower end with both a camming face 278 to force the latching dog 275 into position, and a blocking face 279 which prevents the locking dog 275 from moving out of its operative position when the piston 283, and the linkage member 277 attached to the bottom thereof, are in their lowermost positions. Thus, there is no way for the locking dog 275 to be moved out of contact with the well member 267.

In FIGURE 8 another modification of the connector of FIGURE 6 is illustrated wherein a double-acting piston 383 has been provided with

fluid ports

387 and 388 for introducing a pressure fluid to opposite sides of the piston. A recess 390 is formed in the inner surface of the piston 383 into which the sealing element 392 can expand in its inoperative position. Fluid passage means 395 are also included above the sealing element 392 to permit well pressure to act against the top of the piston 383. In this arrangement, hydraulic pressure must be employed to actuate the piston and any locking dogs (not shown) connected thereto in both directions, since no spring is employed to load the piston and force the locking dogs to their operative position.

In FIGURE 9, another form of a connector is shown which is provided with latching dogs 475 fixedly secured to the lower end of spring-like linkage members 477 which in turn are secured to the lower end 496 of a piston 483. The piston 483 is sealed in a fluid-tight manner by means of O-

ring seals

484 and 485 against the inner wall of the body member 454455. A spring 482 above the piston 483 normally forces the piston downwardly together with the attached linkage member 477 and locking dogs 475. At the same time the camming face 494 on the piston 483 forces the annular sealing elements 492 against the outer surface of the well member 467. If desired, additional seals may be provided such as static seal 492a and a seal 49211 mounted in compression between the top of the well member 467 and the seating shoulder 465 of the body member 454455. In the operation of the connector of FIGURE9, a pressure fluid normally would be applied through port 488 to raise the piston 483 upwardly, retracting the dogs 475 and allowing the seal 492 to extend inwardly into the body member 454-455, prior to lowering the connector onto the well member 467. When the connector 454455 was seated on the well member 467, pressure fluid to port 488 would be discontinued, thus allowing spring 482 to force piston 483 downwardly actuating the annular seal 492 and the locking dogs 475. However, it is to be understood that the connector of FIGURE 9 could also be attached merely by forcing it down on the well member.

Another arrangement of an operating piston 583 is shown in FIGURE 10 wherein hydraulic fluid may be supplied through

ports

587 and 588 to drive the piston 583 in opposite directions without the use of a spring. Recess 590 is provided in the opposite wall of the piston to permit the .annular sealing element 592 to expand thereinto. When the piston 583 is raised to its uppermost position prior to removing the body member 554555 from a well member 567.

I claim as my invention: 1. A wellhead connector assembly comprising a body member having a passage extending axially therethrough, said body member being positionable and connectible in axially telescopic relation with a longitudinally projecting well member having an axial passage therethrough forming an unimpeded throughbore passing through said body member and said well member, said well member being of a size to fit within the passage of said body member,

cooperating connector means carried in the adjacent walls of said body member and said well member,

one portion of said connector means comprising shoulder means formed on the outer wall of said well member,

the other portion of said connector means comprising shoulder-engaging locking means carried by said body member in recesses in the adjacent wall thereof in a position for registering with said shoulder means,

at least the wall of each recess toward the end of the body member which is first in telescopic relation with said projecting well member being diagonallydirected toward said end of said body member,

said locking means being diagonally movable along said diagonally-directed walls of said recesses into and out of engaging relation with said shoulder means,

a plurality of circumferentially-disposed spring-finger actuating means carried by said body member for radial and axial movement relative to said body member and being operatively connected to said locking means when urging said locking means to a locked position in engagement with said shoulder means whereby said engaged locking means prevents relative axial separation of said body member and said well member,

said diagonally-directed walls of said recess blocking movement of the locking means away from engagement with said shoulder means when forces are applied to separate axially said body member and said well member,

blocking means separate from and independent of said actuating means carried within said body member independently and outwardly of said locking means, said blocking means being movable to a position adjacent said locking means to block movement of said locking means from a locked position thereof,

piston means operatively connected to said blocking means for moving said blocking means relative to and independent of said locking means, said body member having conduit means in the wall thereof which pressure fluid is communicable to said actuating means, and

annular packing means carried by one of said members on the wall carrying a portion of said cooperating connector means and axially-displaced therefrom for sealing off between the adjacent walls of said body member and said well member.

2. The apparatus of claim 1 wherein said body member includes port means through the inner wall thereof in communication above said annular packing means between the axial passage in said body member and the space above said piston means whereby well pressure being applied through said port means urges said piston means and blocking means to the blocked position.

References Cited by the Examiner UNITED STATES PATENTS 965,286 7/1910 Ferguson 285-314 2,092,116 9/1937 Hansen 285--314 2,344,740 3/1944 Shaft 2853 16 2,609,836 9/1952 Knox. 2,631,872 3/1953 Wurmser 2853l6 2,887,124 5/1959 Mehl 285306 2,897,895 8/ 1959 Ortloff. 2,962,096 11/ 1960 Knox 285-83 3,052,299 9/ 1962 Geer. 3,071,188 1/1963 Raulins.

CARL W. TOMLIN, Primary Examiner.

Claims

1. A WELLHEAD CONNECTOR ASSEMBLY COMPRISING A BODY MEMBER HAVING A PASSAGE EXTENDING AXIALLY THERETHROUGH, SAID BODY MEMBER BEING POSITIONABLE AND CONENCTIBLE IN AXIALLY TELESCOPIC RELATION WITH A LONGITUDINALLY PROJECTING WELL MEMBER HAVING AN AXIAL PASSAGE THERETHROUGH FORMING AN UNIMPEDED THROUGHBORE PASSING THROUGH SAID BODY MEMBER AND SAID WELL MEMBER, SAID WELL MEMBER BEING OF A SIZE TO FIT WITHIN THE PASSAGE OF SAID BODY MEMBER, COOPERATING CONNECTOR MEANS CARRIED IN THE ADJACENT WALLS OF SAID BODY MEMBER AND SAID WELL MEMBER, ONE PORTION OF SAID CONNECTOR MEANS COMPRISING SHOULDER MEANS FORMED ON THE OUTER WALL OF SAID WELL MEMBER, THE OTHER PORTION OF SAID CONNECTOR MEANS COMPRISING SHOULDER-ENGAGING LOCKING MEANS CARRIED BY SAID BODY MEMBER IN RECESSES IN THE ADJACENT WALL THEREOF IN A POSITION FOR REGISTERING WITH SAID SHOULDER MEANS, AT LEAST THE WALL OF EACH RECESS TOWARD THE END OF THE BODY MEMBER WHICH IS FIRST IN TELESCOPIC RELATION WITH SAID PROJECTING WELL MEMBER BEING DIAGONALLYDIRECTED TOWARD SAID END OF SAID BODY MEMBER, SAID LOCKING MEANS BEING DIAGONALLY MOVABLE ALONG SAID DIAGONALLY-DIRECTED WALLS OF SAID RECESSES INTO AND OUT OF ENGAGING RELATION WITH SAID SHOULDER MEANS, A PLURALITY OF CIRCUMFERENTIALLY-DISPOSED SPRING-FINGER ACTUATING MEANS CARRIED BY SAID BODY MEMBER FOR RADIAL AND AXIAL MOVEMENT RELATIVE TO SAID BODY