US3249056A

US3249056A - Well pumping process and apparatus therefor

Info

Publication number: US3249056A
Application number: US358807A
Authority: US
Inventors: Lyles Cecil Ray
Original assignee: Individual
Current assignee: Individual
Priority date: 1964-04-10
Filing date: 1964-04-10
Publication date: 1966-05-03
Anticipated expiration: 1983-05-03

Description

4 Sheets-Sheet 1 INVENTOR.

C. R. LY/ ES ATTORNEY 2 4 iB O .B O 4 6 1 7 5 2O 5 2 3 3 7 2 .i 2 3 4H 2 y /7/7 /IHI lul l.. /f/ 2 l 2 E@ 3. 2 x3 2 6 2 7 4 2 I n l W 2 A Q M AM, l 2 inn- 2 2 f@ j 5 5 8 A A 5 2 w17 frio. N 3 4 (A. I 6( 59 wm %497 22 i7 21422 al 4 WELL PUMPING PROCESS AND APPARATUS THEREFOR Filed April lO, 1964 May 3, 1966 F/GE ISS 104 May 3, 1966 c. R. LYLES 3,249,056

WELL PUMPING PRGCESS AND APPARATUS THEREFOR Filed April 1o, 1954 4A 4 sheets-sheet 2 *kum* 47 CRU/LES IN VENTOR.

ATTORNEY c. R. LYLEs 3,249,056

WELL PUMPING PROCESS AND APPARATUS THEREFOR May 3, 1966 4 Sheets-Sheet 3 Filed April lO, 1964 /IOO ATTORNEY May 3, 1966 c. R. LYLEs Y 3,249,056

WELL PUMPING PROCESS AND APPARATUS THEREFOR `Filed April 10, 1964 4 Sheets-Sheet 4.

F/GQ F/G/O F/G. F/G. /2

1 7 m 357 26x d 4, 1 /7 I l 21o 21o Il ,234 5 `\`24O i 226- I' 352\ 255 f \35o i350 g L 218 \2[9 -296 274 l I lOA 247 /239 35! 248/ 4249 353/ y l y Il 251 4 f, 4 II 25o' 236 l i i f 27|-/ll '\2o4 l A 347 14A 204 9B 237239 2 9A 235252526 12A 27| I QCA 238 238A 232 20s 79 INVENTOR FIG/5 3 CRLYLES ATTORNEY United States Patent O 3,249,956 WELL PUMPING PRQCESS AND APPARATUS THEREFOR Cecil Ray Lyles, R0. Box 836, Farmington, N. Mex. Filed Apr. 10, 1964, Ser. No. 358,807 4 Claims. (Cl. 10S- 52) This invention relates to a process of pumping oil and gas wells and -to an apparatus adapted to raise Well fluid from the bottom of such wells for use in such process.

One object of this invention is to provide an improved external bypass gas-lift apparatus.

Another object of this invention is to. provide a gas-lift plunger of particular utility in oil wells wherein the gasoil ratio is particularly high.

Still another object of this invention is to provide a sturdy gas-lift piston plunger providing a minimum number of parts and an improved seal and means for automatically reversing its direction of travel at the upper and lower limits of its travel.

Another object is to provide an improved method of unloading low oil-gas ratio oil and gas wells.

Other objects of this invention will become apparentto those skilled Vin the art upon study of the below description, of which description the hereto attached drawings form a part and in which drawings the same numbers refer to the same part throughout all the drawings and wherein- FIGURE l is a generally cross-sectional view and partly broken away of an apparatus according to this invention shown in its expanded condition. This sectional view is taken generally along the central longitudinal plane shown as lA-IB in FIGURES 7 and 15;

FIGURE 2 is a top view of the apparatus of FIG- URE l, said apparatus being here also shown in its eX- panded condition, and as viewed along the direction of the arrow 2A of FIGURES 7 and 15.

FIGURE 3 is a generally cross-sectional View through the apparatus of FIGURE 1 in its contracted condition, said view being taken generally along the direction of the central longitudinal plane 3A--3B in FIGURES 8 and 16;

FIGURE 4 is a top view of the same apparatus as shown in FIGURE 3 in the -sarne contracted condition of its parts as shown in FIGURE 3 and as Viewed along direction of arrow 4A of FIGURES 8 and 16;

FIGURE 5 is a diagrammatic representation of Ithe apparatus of FIGURES 1-4 during the operation of that apparatus in a well tubing and showing that apparatus in two of its operative positions therein with its sealing means in its expanded condition;

FIGURE 6 is a diagrammatic representation of the apparatus of FIGURES 1-4 during its operation in a well tubing in two of its positions therein with the sealing means of that apparatus shown in its contracted condition;

FIGURE 7 is a transverse cross-sectional View of the apparatus shown in FIGURE 2 taken along the plane shown as section 7A7B of FIGURE 2;

FIGURE 8 is a transverse cross-sectional View of the apparatus as shown in FIGURE 4 along this View being taken along the plane shown as section 8A-8B of FIG- URE 2;

FIGURE 9 is a view of the interior surface of sealing element 204 as seen along the direction of the arrow 9A in FIGURE 10;

FIGURE 10 is a side view of the dumbbell-shaped sealing element 204 as seen along the direction ot' the arrow 10A in FIGURE 9;

FIGURE 11 is a view of the interior surface of one of the tb shaped (phi-shaped) sealing elements 226 as seen along the direction of the arrow 11A in FIGURE 12;

FIGURE 12 is a side view of the 1J-shaped sealing 3,249,056 Patented May 3, 1966 'icc element 226 as seen along the direction of arrow 12A in FIGURE 14;

FIGURE 13 is an end view of the sealing element 204 as seen along the direction of Ithe arrow 13A in FIG- URE 9;

FIGURE 14 is an end view of the sealing element 226 as seen along the direction of the arrow 14A in FIG- URE 11;

FIGURE 15 is a tranverse cross-sectional view of the apparatus as shown in FIGURES 1 and 2 as seen along the plane shown as section 15A-15B in FIGURE 2;

FIGURE 16 is a transverse cross-sectional View of the apparatus as shown in FIGURES 3 and 4 and as seen along -the plane shown as section 16A-.16B of FIG- URE 4.

The apparatus of FIGURES 1, 2, 3 and 4 is generally indicated as 21 and comprises a frame subassembly 30, a piston subassembly 32, and a sealing subassembly 34.

The apparatus 21 is intended to operate in a Well, gen-- erally shown as 25. The Well comprises a tubing string 23, which is composed of lengths of tubing as 39, 40 and 41 with adjacent lengths, as 40 and 41 joined by collars, as 42. The tubing string has conventional perforations as 46 at the level of the formation 45 which permits cornmunication and ltransport of the formation fluids and gases to the interior 47 of the well string. The tubing string is provided with a discharge orifice 48 leading to a discharge outlet 49 above the level of the ground surface 44 of the well 2S. The tubing string extends from the discharge outlet and orifice to and through the formation 45. A conventional valve 5|) may be used on outlet 49 to stop the well or cap it in as desired.

An upper stop 51 is so located within the tubing string interior 47 so that the top of .the Valve sealing subassembly 34 of the apparatus 21 does not rise above the bottom of the discharge orilice 48 where that orifice opens into the interior 47 of the string 33.

The lower collar stop is a conventional collar stop (such as in United States Patents 2,213,580 or 2,352,612.) and is located slightly above the top of the production zone formation 45 and below the usual top'level, 60, of Ithe oil or other uid 61 within the well tubing.

This conventional collar stop is positioned between the bottom of one length of tubing as 41, and the top of another length of tubing as 42, in the space between the collar stop in the preferred embodiment.

In operation of the apparatus of this invention, the device 21 moves between the bottom stop 55 and the upper stop 51. Firstly, a bottom stop as 51 is set in the well tubing. This stop is set at a level suciently below the intial top level of oil 60 in the Well for continued repeated location of a piston plunger as 21 with the top of its sealing subassembly 34 below the top level 69 of the oil or iluid 61 in said well to be below lthe top of the level of said iluid or oil allowing for the fall of said level during production of gas and fluid from said formation. However, the level of the stop 55 is located so that the bottom of the sealing subassembly 34 of apparatus 21 is maintained above the top of the level of the perforations as 46 in the tubing.

The apparatus 21 with its sealing subassembly 34 in the expanded condition shown in FIGURES 1, 2 and 5, smoothly and slidably tits into the interior of the tubing in which it is intended to operate, as 41, and forms a resilient yet gas-tight seal therewith. In operation the apparatus 21 is placed in the well string 23 with the sealing subassembly in its contracted condition as shown in FIGURES 3, 4 and 6. The apparatus 21 with the sealing subassembly 34 in its contracted condition then drops from near the top of the well, as shown in position 64 in FIGURE 6, to the lower portion of the well, as shown at position 66 in FIGURE 6, above yet near the lower stop 55. In travel from the position 64 to 66 the valve sealing subassembly .is in its contracted position, as shown in FIGURES 3 and 4 and provides', as also shown in FIGURES 8 and 16, a minimum transverse cross-section. This reduced cross-section provides for-an external bypass of fluid past apparatus 21 and a minimum of resistance in the passage of said apparatus 21 through upowing gases and well fluids. This passage is further improved by the streamline shape of the longitudinal section of the apparatus 21, which longitudinal section is shown in FIG- URESl an-d 3.

At the lower position, as 66, the bottom tip 68 of the rod 70 of the pistonsubassembly 32 projects below the bottom of the frame subass-embly 30 in the manner shown in FIGURES 1 and 2. The rod-holding subassemblies 107 and 109 of the sealing subassembly serve to hold the rod and sealing subassemblies in the position thereshown or below described.

The space 100 between the periphery of the contracted sealing subassembly elements and the interior surface of the tubing permits a rapid fall of the tool 21 down the tubing notwithstanding a concurrent substantial upward flow of gas. Accordingly the apparatus permits a continued and uninterrupted flow of gas from the well 25 notwithstanding the downward travel of the apparatus 21 therethrough.

The apparatus 21 falls freely through the well tubing and the o-il in the tubing until it meets the top of the lower stop 55.

The impact of the movement of the tool 21 against the stop 55 on the projecting pin 68 overcomes the force of the rod-holding subassemblies 107 and 109 holding the piston and sealing subassemblies in the position shown in FIGURES 3 and'4 and the end 68 of the rod 70 is driven inward and upward into the frame subassembly to the position shown in FIGURES l1 and 2. This movement of the rod 70 from the position shown in FIGURES 3 and 4 to that shown in FIGURES 1 and 2 releases toggles as 4711 and expands the sealing subassembly to its sealing position across the interior of the tubing as is shown in FIGURES 1, 2, 7 and 15. The fan of the plunger down the well and contact with the lower stop 55 thus results in automatically rearranging of the sealing subassembly components at the bottom of the well and effects a substantially gas-tight seal across the tubing, and below the top level 60 of the oil and/or other fluid in the tubing.

Thev orientation of the sealing subassembly components as shown in FIGURES l, 2, 7 andl 15 blocks the free upward passage of the gas and oil. The gas pressure of the formation gas below the expanded sealing subassembly 34 then drives the expanded plunger 21 with a load of iiuid and/or oil as 83 thereabove from a position 81 near the bottom stop up the well to an upper position 85 as shown in FIGURE 6.

This oil thus carried up the tubing by apparatus 21 is unloaded from the well at position 85 near the top of the well into a collector tank, or line 87, through the well dis'- charge 49.

After the load of oil has been discharged the continued upward motion of the plunger 21, which motion is due to that the plunger is still impelled by the pressure of the gas 89 therebelow, to the position 64 whereat the upper stop 51 forcefully contacts the upwardly projecting tip 91 of -rod 70 as shown in FIGURE 5. The striking of the projecting tip 91 with the top stop overcomes the positioning force of the rod-holding subassemblies 107 and 109 and moves the rod 70 of the piston subassembly downward and into the frame subassembly 30 as shown in FIGURES 3, 4 and 6 and, as below described, causes the sealing subassembly 34 to assume its contracted condition. This forceful contact at the position 64 thus automatically rearranges the components of the sealing subassembly relative to the frame subassembly from that arrangement thereof shown in FIGURES 1 and 2 to that shown in FIGURES 3 and 4. This removes the seal theretofore effected by the subassembly 34 across the tubing and interior of the tubing string.

The weight of the plunger 21 then drives that plunger from position `64 toward ythe bottom of the well 25. The small cross-section of the plunger apparatus relative to the internal cross-sec-tion of the tubing, as shown in =FIG URES A16 and 6, especially coupled with the fact that the space 100 available for passage of iluids such as well gas, oil and water, past the plunger 21 is unobstructed and permits straight-line ilow of such iluids past that plunger. This provides that the plunger 21 travels down the well in 6 minutes to a depth of 6,000 feet in 2-1/2 linch tubing with a great velocity even in wells that produce 1,000,000 cubic feet of gas per day against a line pressure of 500 to 550 p.s.i. and permits that downward passageof plunger 21 without interfering with the concurrent upward flow of gases from the formation 45 and out of the well tube discharge 48.

The structure of the piston 21 below described permits that it `be relatively light in weight although extremely sturdy in order to perform its intended function of rapid downward passage through the well to re-form an effective yet exible seal across the bottom thereof and, because of such light weight, to require a minimum of pressure for upward drive thereof by the formation gas.

On return to the bottom stop l51, plunger 21 is again located .below the top level 60 of the fluid and/or oil, 61

r in the well and the cycle of operation abo-ve described for movement of the plunger 21 and the fluid thereabove as 83 is again repeated.

The simple sturdy structure of this apparatus with relatively large component pieces permits the absorption by the apparatus of the impact resulting from repeated rapid falls through great heights repeatedly without damage to this apparatus.

The collar` stops 51 and 55, have, at their point of contact with the top end 91 and bottom end 68 of the rod 70 a greater width than the diameter of those rod ends. Accordingly, the movement of `the piston `rod 70 is limited to the yamount by which the ends thereof, as tip 68 and tip 91, project ybeyond the topedge 102 and bottom edge 104 of the frame subassembly 30. Accordingly, after such limited motion of the rod 7 0, the remainder of the impact due to the motion of the apparatus 21 is absorbed by the frame subassembly 30 and, more particularly, its top edge 102 or botto-m edge 104, and the movement of the rod 70 is limited by nuts 153 and 164.l

In a particular embodiment -of the apparatus of the FIGURES 1-4 for coventional tubing with a nominal 21/2 inch internal diameter, the dimensions of the apparatus are as in Table I herebelow.

The piston assembly 32 comprises a rod 70, an upper rod-holding subassembly 107 and a lower rod-holding subassembly 109.

The rod 70 comprises all firmly joined together as one integral piece a central cylindrical section 111, an upper frusto conical section 113 and a `lower frusto conical section 115, an upper locking shoulder 117, a lower locking shoulder 1119, an upper point shaft 11211, `and a lower point shaft 123. The upper point shaft 121 is a solid cylindrical shaft with a projecting tip 91. The upper locking shoulder is a .right cylindrical member of larger diameter than the point shaft 121 and provided with a cavity and resilient locking means, below described, forming part of the upper rod-holding subassembly, 107. The upper frusto conical section 113 is a right cylindrical cone and is coaxial with both the cylindrical shoulder 117 and the upper point shaft 121. The outer diameter of the fru-sto conical section 113 meets with the outer 'periphery of section 117 .at the edge 118. The bottom portion of the conical portion 1113 is joined by edge 120 to cylindrical section 114 and section 114 is joined to rthe sturdy solid cylinder i1-1'1. The lower edge 1120 of the frusto conical section 113 meets a cylindrical section 114 with a smaller external diameter than the edge 118.

The difference between these diameters of sections 114 and 117 is related to the movement of the sealing subassembly components as below described. The solid cylinder 11.1 at its lower edge 112 is joined to a solid frusto conical section 115 which is a solid piece of steel with the periphery of a cone, which right cylindrical cone has a conical surface which has a central axis which is the same as the axis rof the cylindrical portion 111, as well as of frusto conical 113. The surface of the frusto conical portion 115 has the same slope relative to its central axis as does vthe surface of conical section 113 to its axis. The bottom edge 116 of the portion 115 joins a cylindrical portion 116 of the same size as the cylindrical portion 114. The lsolid cylindrical portion 116 is joined to a' shoulder 119 which has a right cylindrical outer surface of solid steel within which are located com# ponents of the lower rod-holding subassernbly 109 below described. This lower locking shoulder is firmly attached to the cylindrical shaft point 1122 which has a smaller external diameter than the locking shoulder to provide for the locking action below described. The lower point shaft 122 is cylindrical and coaxial with elements 119, `116, 115, 111, 114, 113, 117 and 121, all of which elements are coaxial with each other. The point shaft 122 ter-Ininates in a lower point 32 which, in the position shown in FIGURES 3 and 4, projects below the lower edge 104 of the frame subassembly 30. The yupper extremity or tip 91 of the upper point shaft 121 projects above the shoulder 102 of the frame subassembly 30 in the position of parts shown in FIGURES l and 2 by the same amount as the point 32 projects in the position shown for the contracted condition of the seal subassembly shown in FIGURES 3 and 4.

The frame subassembly 30 comprises an upper or lishing neck portion 130, a central body portion 132 and a bottom portion 134. In serial order from the top edge 102 of the frame subassembly, the fishing neck portion 130 comprises a cylindrical fishing head 141, a fishing head shoulder 143 and a fishing neck waist 145. The fishing neck waist is joined to the fishing neck head by the shoulder 143. The waist is joined to the body portion 132 by the body shoulder 147. The shing neck portion vis provided with a central cylindrical cavity 149 at the center of said neck in which cavity 149 the upper locking cylinder 117 of the rod 70 is located and moves. A threaded portion 151 of cavity 149 holds a shouldered locking nut 153. The locking nut has a central longitudinal cylindrical cavity 155 therein wherein the point shaft 121 of the rod 70 is firmly yet slidably supported. The point shaft 121 has a smooth yet slidable fit in that cavity 155. The inner portion of the fishing neck portion 130 is also provided with other annular orifices hereinbelow described which cooperate to form the upper rodholding subassernbly 107 below described. The locking shoulder 117 fits into the narrowest portion of the cavity 149 with a smooth yet readily slidable fit.

The bottom portion 134 of the frame subasembly cornprises a sturdy thick-walled outer sleeve 160 traversed by a central longitudinallyextending cavity 161, at the lower end of which is -a thereaded portion 162 in which a shouldered nut 164 is replaceably located. The inner cavity 161 of the sleeve 160 is provided with annular recesses for locking balls, which are below described, forming a part of the lower rod-holding subassembly 109. The nut 164 has a cylindrical passageway 166 therethrough which is coextensive Aand coaxial with cavity 161 and smoothly, yet slidably, lits about the lower point shaft 122 to permit reciprocation of 4said point shaft Within said passageway. The nut 164 has a shoulder 168 which nests into the recess 170 therefor in the sleeve 160. The nut 153 has a similar shoulder 156 similar to 168 which nests into a recess 15S therefor in the fishing head 141. Y

The body portion 132 of the frame subassembly 30 comprises an upper lever-support portion 173, a middle bridging portion 175 and a lower lever-support portion and firmly attached to the fishing neck portion 130. The lower lever-support portion 177 is continuous with and firmly attached to the :sleeve portion 160 of bottom portion 134. The upper lever-support portion 173 and lower lever-support portion 177 are joined by the cylindrical bridging portion 175 and are securely attached thereto inasmuch as the entire frame subassembly may be formed in one piece of metal except for the

nuts

153 and 164. The middle .bridging portion cylinder 175 has an inner cylindrical vchamber 179 which runs through portion 173 and connects with cavities 149 and 161 within which the central cylindrical portion 111 of the rod 70 is slidably yet firmly located. The outer surface of the bridging portion 175 is cylindrical and provided with three groups of vspring holes, one group of such holes, as 188, comprises

springfholes

180, 181, 182,-183 to locate therein springs

such yas

184, 185, 186, and 187 respectively in an upper ring or -group 18S of springs and spring holes therefor, torone end of the dumbbell-shaped

sealing elements

202, 204, 206 and 208.

A lower group of spring holes 189 comprises a similar series of holes for a similar ring or group of springs and spring holes wherein holes 191 and 193 correspond to spring

holes

181 and 183, and the

springs

192 and 194 in said spring holes correspond to

springs

184 and 186; the second ring 189 of springs correspond in size, shape and action to the upper ring of springs 188 and likewise resiliently urge outward the other ends of

elements

202, 204, '206 and 208.

An intermediate -group or ringof springs and spring holes 196 is also provided in the bridging member 175 for action on the shaped

members

220, 222, 224 and 226. The members of this particular group-

holes

401, 402, 403, 404 and springs 405, 406, 407, 40S-are shown in FIGURES 15 and-16. These spring holes in

rings

188 and 189 are equally spaced (at 90) from each other.

.The spring holes in ring y196 are equally spaced at 90 from each other. Each of the spring holes 400, 401, 402 and 403 seat one end of each of the

springs

405, 406, 407 and 408 respectively; the other end of each of such springs seats in the spring hole of a i5-shaped member as 220, 222, 224 and 226, respectively.

The ring 196 is halfway between the

rings

188 and 189. The upper lever-support section 173 is provided with four equispaced radially extending lever slots as 410, 412, and 414 which are shown, as well as another lever slot, opposite 4to lever slot 412 which particular slot is not shown in the drawings. These slots extend yfrom chamber 179 to the surface of section 173. In each of these slots a vlever such as 411 (in slot 410) and 413 (in slot 412) and 415 (in slot 414) is pivotally supported. Cylindrical pivot pins 416, 417, and 41S pivotally support each of the

levers

411, 413, and 415 respectively and are themselves firmly supported in the upper lever support section 173. Pin 416 is provided for lever 411, and pin 413 is provided for lever 415, and similar pins are provided for the other levers to permit such Ilevers to rotate about the axis of the pivot pins therefor.

The lower lever-suport section 177 is provided with four equispaced radially extending lever slots, as

slots

420, 422 and 424 which are shown as well as another lever slot opposite to toggle slot 422 which particular slot is not shown in the drawings. These slots extend from chamber 179 to the surface of section 177. In each of these slots .a lever such as 421 (in slot 420) and 423 (in slot 422) and 425 (in slot 424).is pivotally supported on cylindrical pivot pins as 426, 427 and 428. The

pins

426 and 428 pivotally support each of the

llevers

421 and 423 respectively, and similar pins are provided for .the other levers to permit such levers to rotate about the axis of the pivot pins therefor. The 'lengths of the pivot pins 416, 417, 41S are each firmly yet releasably secured into the adjacent lever support portion 173 of the frame subassembly in a plane normal to the longitudinal anis of the rod 70 and at the same distance from said axis. lengths of pivot pins 426, 427, 428 are each rmly yet releasably secured into the portion 177 in another plane parallel to that of lthe length of pins 416, 417, 418 in a plane normal to the longitudinal -aXis of rod 70 and at the same distance from said axis.

Each toggle is provided with a pin as pin 226 for toggle 221 and pin 227 for toggle 225. All the levers are identica-l in shape and size to each other; all .the lever slots are similarly identical in their shape and size; all the lever suport pins are located the same distance from the central longitudinal axis of the rod 70.

The sealing subassembly 34 comprises a lirst series of like generally dumbbell-shaped

elements

202, 204, 206, 208 in an expansible nesting relationship with a second series of

Ilike elements

220, 222, 224, 226, generally shapedl like the Greek letter c (phi).4 The

elements

202, 204, 206 and 208 are referred to as durnbbell-shaped because each has two peripheral enlarged portions joined by an intermediate narrow bridging portion. For element 204, as an example, the large peripheral elements are 210 and 212. These are cunved in secti-on (asin FIGURE 7) and square in outline in plan view. 'Ihose enlarged elements are mirror images of each other and joined by the intermediate bridging member 214 that ext-ends the full length of element 204. The other dumbbel'l shaped elements have the same structure and are also symmetrical about the central longitudinal plane 9B-9C. The thickness of the vbridging member is the same .as the thickness of the lateral portions, as 218 and 219 of the element 210.

The central portion of each portion of the dumbbellshaped elements as 210 and 212 is provided with a spring hole for the location of a spring, as hole 240 in portion 210 and the spring hole 242 in portion 212. Likewise, the element 208 has corresponding spring holes 241 and 243 corresponding to the spring holes 240 and 242 in the element 204.

The elements resembling the Greek letter phi and referred to as qta-shaped

elements

220, 222, 224 and 226 are referred to as phi-shaped (g-shaped) because, as shown for elements 226 which is 'shown in some detail in FIG- URES 11, 12 and 14, such element consists of a central wide portion 232 with

narrow arms

234 and 236 extending therefrom.

Elements

202, 204, 206 and 208 are identical to each other and the description given for one such element, i.e., 226, is applicable to corresponding elements.

The central wide portion 232 of the element 226 has a *curved cross section identical to that of portion 210 of element 204. The

narrow arms

234 and 236 are identical in cross section to portion 214. Each p-shaped

element

220, 222, 224, 226 has a spring hole as 293, 294, 295 and 296 respectively for `a

spring

402, 403, 404 and 405, respectively.

Springs as 185 lit into the spring holes 240 and 281 and urges the element 204 and element 175 apart; similarly spring 187 fits in the spring hole 183 and the spring hole 241 and urges element 208 outwardly of element 75.

The spring 192 which is located in spring holes 191 and 242 cooperates with the spring 185 to press the element 204 outwardly and to the right, as shown in FIG- URE 1. The spring 187 .and the spring 194, each located in holes in the central bridge portion 175 and in the element 208, serve to urge the element 208 leftward and outward. This outward urging is resisted by the inner wall 197 of the tubing 4when the apparatus is in its expanded condition, as in FIGURES 1 and 2 and thereby a resilient seal is formed between the subassembly 34 and wall 197.

When the apparatus 21 is in its contracted condition, as in FIGURES 3 and 4, the levers as 411, 413, 415, 421, 423, and 425 which are actuated bythe rod 70 and overcome the outward force of said springs on the dumbbelled l and b-shaped sea-ling subassembly components.

Thev

The levers as 211, 2113, 215 421, 423, Land 425 do not permit sealing suba'ssembly components to move as far out as the thickness of the sealing subassernbly components-Le., the thickness from inner surface 237 -to outer surface 238 of element 204-althou1gh usually such elements are permitted to travel no further outward than the thickness of the enlarged portion of :the sealing subassernbly components, .i.e., the distance from surface 239 to surface 238 on FIGURE 13 or corresponding thickness 239A to 238A on FIGURE 14.

Each of the sealing elements has an inner curvature which matches fthe outer 'curvature o-f the bridge 15715. The outer surface of each element, as 238 and 238A o'f elements as 204 and 226 has the same -radiusof curvature as the inner surface 197 of the tubing 411 in which the tool 21 is used. The width as `measured from edge 245 to another llateral edge 247 Vof element 212 is su'fliciently of such size that when the

elements

204, 206 'and 208 nest as `shown in FIGURES 4, 8 'and 16 with the capeshaped portion 232 of the p-shaped portion interdigitating with capes as 210 and 212 on the dumbbell-shaped portion. This relationship is shown in FIGURES 7, 8, 15, and 16. The portions 214,A 234 Iand 236 all have the same cross-section. Similarly, the

cape sections

210, 212 and 232 have the same cross-section. Accordingly, the arms as 234 and 236 of ele-ment 226 ne'st lbelow the capeshaped portions of adjacent dumbbell-shaped portions of 208 and 206 as does the portion214 of the element 226V nest between the surrounding :cape portions of

elements

222 and 224.

The limited width between the lateral edges as 24'5 and 247 of each of the dumb-bell-shaped elements permits their contraction to the position shown in 'FIGURE 8. Similarly, the distance between the

lateral edges

2,48 and 249 of the cape portion of shaped elements such as 226 permit the nesting of similar jb-shaped elements in contracted condition of the subassemb-ly 34 as shown in FIGURE 16. The width of the

arms

234 and 236 and of the bridging element 2114 are such as to permit their nesting as shown yin FIGURES 16 and 8. Nevertheless, t-he Width of arm 236, i.e., between edges 250 and 2'5l1, is lsuch as to permit effective blocking :thereby of the space between the edges of the adjacent capes of dumbbell-shaped element as shown for element 234 in `FIG- URE 8. This accordingly provides a substantially gastight sea'l (between one 4dumlbhell-shaped sealing element and the net notwithstanding the radial expansion of the du'mbbell-shaped elements and the (1b-shaped elements during the operation of this device. The outer surface as 2'54 `of each bridging element 'as 2l14 in the dumbbellshaped element lmatches the internal curvature of the inner surface as 255 of the cape portion of the adjacent q-shaped elements and thereby provides `a smooth contact and seal therewith and an even urgingV outwards by the IVarious springs 184-187 and 402, 403, 404 and 405. Each of the dumblbell-shaped elements is provided at either end of the cape element with a pair 'of recesses as 261 and 271 for element 204, and recesses 2613- iand 273 for element V202, Vand recesses 267 and 275 `for dumbbellshaped element 20S. The tongue 262 of element 2x11 ts into :the recess 261. The tongue 264 lits into the re'cess 263. The tongue 264 of the lever 413 nts into the recess 263 of element 202. The tongue 265 of fthe element 415 dits into the :recess 265 of element 208. Similarly the tongue 272 of the element l421 ts into the recess 271 of element 204. Similarly, the tongue 274 of lever 423 fits into the slot 273 of the element 202 and similarly the tongue 276 of lthe toggle 426 lits into fthe recess 275 of the element 208.

The arrangement of the conical portion of the rod 70 is thus, as `shown in FIGURE 3, that on movement downward of the control rod 70 the plate lingers which yfollo'w the `contour of that rod are urged into the position shown in FIGURE 3.

All thesealing element control levers, as 411, 413, 4115,

9 421, 423 and 425 which are shown are all identical in shape and size. Each toggle platte as 415 comprises a nger portion 280 which is at one end of a sensing arm 281. The arm 281 has a pivot hoie 282 :therein for reception of a pivot pin as 218 about which such arm may pivot. The tongue portion 283 of the arm extends out to the tongue of said toggle, as 266. The tongue portion contacts the bottom of the recess corresponding thereto on the sealing member and in the contracted position of the sealing subassernbly urges that particular portion of the member 20S and also the portion of

members

226 and 220 below member 208 in toward the rod 70. The finger 280 is guided in its position accordingly by the location of the rod 70. In the lowered position of the rod 70 shown in FIGURES 3 and 4, the finger 280 and all corresponding ngers of similar toggles are forced radially outward and the tongues, as 262, 264, 266, 272, 274 and 276, are forced inward and bring inward the corresponding plate, as 202 for `

fingers

254 and 274, 204 for fingers 262 and 272, and

tongues

274 and 276 for element 208. The e-shaped plates 220, 2212, `224- and 226 are controlled in their position by their springs (184, 185, 186, and 187) which urge them outward.

Accordingly, motion of the rod '70 urges the lever tongues inward. The movement of the tongues -inward moves the dumbbell-shaped elements inward. The ib-shaped elements ``which are restrained lfrom outward movement by the cape portion of the dumbbell-shaped elements and are urged outward by thei-r springs `as 203, 205, 207 and .209 closely follow the control provided for the expansion and contraction by the levers las 4111, 413, 415, etc., which in turn are controlled by the motion of the rod 70. Y

lThe amount of motion provided :for by the levers is B1, change in ldiameter in :the preferred embodiment herein described in particular detail 'for use in pipe of 21/2 inch nominal internal diameter. The actual requirement for motion through the tube is only /6 inch change to the actual 2.44 inch diameter of such pipe so this structure allows a somewhat greater increase change in diameter of the sealing -subassembly than the maximum internal diameter of the tube. This results in a firm yet resilient lit of the sealing elements with the tube at all times, notwithstanding fthe sealing subassembly also is readily -resiliently contracted to compensate for the usual variations in internal diameter of such tubing such as to the 2.35 inch drift diameter of such tubes. The length of the sealing subassembly 34 also avoids any loss of pressure when passing joints between tubing joints. i

Control rod 70 is provided with an upper rod-holding subassernbly 107 and a lower rodaholding subassernbly 109. Subassembly 107 comprises element 117 and recesses 308 and 309. Element 117 is provided with a transverse hole 300 therethrough. A spring 302 is provided within that hole and locking balls 304 `and 306 are located within that hole: These are movable in the hole 300. The locking

balls

304 and 306 are each slightly smaller in diameter than the internal diameter of the hole 300 which allows the balls to sink into the hole during the motion of the rod from the position shown in FIGURE 3 to the position shown in FIGURE 1.

Lower annular recess 308 is provided for locating the

balls

304 and 306 in their position shown in FIGURES 1 and 2. Additionally, upper annular recess 309 is provided for location of said locking balls in the position shown for FIGURE 3. The

recesses

308 and 309 have a semicircular cross section that matches the size and shape of

balls

304 and 306. The longitudinal spacing of these

recesses

308 and 309 is the distance ofthe longitudinal movement of the rod 70 in moving from the position shown in FIGURE 3 to that in FIGURE l. Subassem-bly i109 comprises shoulder 119 and recesses 317 and 319. The lower locking shoulder `119 is also provided with a passageway therethrough, 312, with a spring 313 therein going diametrically thereacross and with Spherical locking balls I314 and 315. The balls smoothly lit passage 312 and are urged firmly outward of the passage 3-12 and into and against the bottom of recess 317 or' top of

recess

3,19 by the spr-ing 313 in the -hole 312. A lower 4annular recess 3'17 on the lower cavity in sleeve 160 has a curved lower portion and lan angled but straight upper portion 318. An annular recess which is the mirror image of 317 and 31S is provided at 319 and 320. These two recesses, in combination with spring 313 and

balls

314 and 315, provide a resilient snap action to hold the shoulder 119 in the lower position shown in FIGURE 3 or in the upper position shown in FIGURE l. It will be noted that the lower surface 321 of the shoulder 119 meets the top of the nut 164 when in its lowered position as shown in FIGURES 3 and 4. This provides for receipt of the impact of the shock of upward motion on the upper stop 533 as in FIGURE 46 by the threaded portion of the nut 164 and the passage of such shock to the bottom of the bottom portion 134 of the frame subassembly.

On the motion of rod 70 to its upper extremity to the position shown in 'FIGURES l and 2, the upper shoulder 332 of the element 117 meets the lower sur-face of Ithe locking nut and thereby serves to distribute the im pact of the shock -rnet on impact of the tool 21 with the l lower collar stop 55 as shown in FIGURE 6 at position 66.

The resilient suspens-ion of the qx5-shaped elements on

springs

184, 185, 186, 187 with restraint on the shaped elements only by the dumbbell-shaped elements so far as outward movement is concerned, and the close tit ot the squared edges of cape elements as 232 against the squared edges of element as 210 and 212 in the expanded condition of the sealing subiassembly provides a iirm diametral gas tight seal notwithstanding the relative looseness of tit prior to application of gas pressure to the expanded seal subassembly prior to the beginning of upward motion of apparatus 21 from position 66. The longitudinal peripheral spaces between

elements

202, 204, 206 and 208 are not contiguous with the peripheral longitudinal spaces between sealing

elements

220, 222, 224, 226 and those sealing elements do smoothly tit the wall 197. This improves the diametral sealing action of these sealing elements. Also, the external surfaces, as 236, on each of the i5-shaped elements form a good radial gas seal against each of the 4adjacent surfaces as 239 of the dumbbellshaped elements. Also, the upper end edge tot both the dumbbell-shaped and gli-shaped yelements iit smoothly against the wall 333 of the frame body.

Table l Distance Element Ref- Dimension Inches erence N o.

From- To- Internal diameter. 197 197 2. 441

gth 12S/4 13% 0. 735 691s 113 (and 115) la 114 (and 116). 0.375

u 117 1 g/ 735 ll@ 1iin 735 121 and 122 .315

lis 130 lu 1% 141 l s im 25g 2% 173 256 25s 175 1% 204. 3% l l 214 1% 226 3% 232 Length l. 235 236 tand 237). Thickness 237 239 3fm 338 (238A) External curvaturrl 2. 441 237 (and 236)-- 1% External curvature 'the position of parts above-referred-to.

((n=centerline.)

The upper and lower edges of all the dumbbell-shaped elements-as 346 and 347 of element 204- are bevelled to facilitate the upward movement of the expanded sealing subassembly past protuberances and/or irregularities lin the tubing and to permit the ready reversibility of the sealing elements parts for ease and economy in assembly. All the sealing

subassembly elements

202, 204, 206, 208, 220, 2212, 224, 226 and 228 top and bottom halves are symmetrical about the central transverse plane 14A15B of FIGURE 2 and 16A-16B of FIGURE 4 in the preferred embodiment above described.

The central transverse diametral surfaces, as 350 (and 351) of each of the cape-shaped components of .each dumbbell-shaped elements as element 2.10 (and 2-12) of item 226 are smooth and flat to form a rm relatively gas-tight seal with adjacent diametral surface therebelow such as 352 (and 353) of an adjacent cape element such as 232, which surfaces are also hat and smooth, on urging of the longitudinally movable pb-shaped elements Vagainst the dumbbell-shaped elements by gas pressure exerted against lthe 1t-shaped elements through the spaces (as 3155 and 356) between the cape portions of adjacent dumbbell-shaped elements in the expanded condition o'f the sealing subassembly. The surfaces referred to in parentheses are active in seal formation on reversal of Such gas-tight seal is maintained notwithstanding the variation in internal diameter of the tubing and the eifective external diameter of thev sealing elements which are resiliently urged against the interior of such tub-ing.-

A similar smooth lflat surface is formed at the top edge of each dumbbell-shaped element, as 357 on element 204, whereby .to form a smooth yet relatively gas-tight seal against the flat smooth surface 333 of the frame subassembly with such elements as 202, 204, 206, and 208.

The length of the

exterior sealing elements

204, 206, and 208 is greater than most of the spaces between successive lengths of tubing joined by the intermediate collar stop; this avoids any leakage of lgas pressure urging said apparatus 21 upwards as above described past such sealing elements `in the neighborhood of a collar stop The interlocking nesting `of the shaped and dumbbell-shaped elements prevents engagement of any one Iof such elements with the shoulder of a piece of tubing in the region yof the space between tubing lengths at a collar stop. The width of the cape-shaped portions provides a large sealing surface to reduce the effect of wear on the eectiveness of the seal formed by the sealing subassembly 34. The thickness of each o-f the cape-shaped portions, c g. as from surfaces as 239 to surface 238 in element 204 and from surfaces 255 to surfaces as 238A in element 226, is greater than the intended width of the space 100 in the preferred embodiment above described.

The springs as `185 and 1911 for each of the sealing elements of subassembly 34, as element 204, provide a total of 11/2 pounds outward force in the expanded condition of those springs, i.e., 3A pound outward force per spring in the expanded condition shown in FIGURES 1 and 2: the other springs attached to the other sealing elements provide a similar amount of outward force in the same condition. Thus, springs 187 and 194 similarly provide a total of 11/2 pounds outward force in the condition and position shown in FIGURES l and 2. In the expanded condition of the subassembly 34, as shown in FIGURE 1, the levers, as 411, do not bear the force of the springs urging the seals outward because the fingers 280 are then out of cont-act with the reduced cross-section por-tion 114 of rod 70 and 'the springs resiliently urge the corresponding seal elements, as 202, 204, 206, 208, 220, 222, 224 and 226 into contact with the wall 197 with about 1% pound force per spring.

The usual gap between adjacent pipes as 40 and 41 in a string as 23 is about an inch at couplings as 42: each of the sealing element components of subassembly 34 in contact ywith the interior surface 197 of the pipe of string 23 have a greater length as well as that the length of the total expanded subassembly 34 is almost 4 inches long as above listed, and hence the apparatus 211 suffers no interference in its opera-tion due to the usual gap between the pipes at the couplings.

Although i-n accordance with the provision of the patent statutes, particular preferred embodiments of this invention have been described and the principles of the invention have been described in the best mode in which it is now' contemplated applying such principles, it will be understood that the operations, constructions and compositions shown and described are merely illustrative and that my invention is not limited 'thereto and accordingly, alterations and modifications which readily suggest themselves to persons skilled in the art without departing from 'the ltrue spirit of the disclosure hereinabove are intended to be included in the scope of the annexed claims.

I claim:

1. An oil -well appara-tusproviding for an external bypass of Huid therepast for operation in a 'well tubing comprising a frame with a longitudinally extending recess therethrough, rod holding means in said frame, said rod being slidably held in said recess in one of two positions,

toggle means actuated by said rod and pivotally attached to said frame for motion of one pontion thereof inward and outward on upward and downward motion ofthe rod with respect to said frame, two series of sealing elements each of which series circurn'scribe the Vperiphery of said frame, each of the elements of at least one of said series having a spring nested therein and said spring pressing" each of said element outward, one edge of one pontion of said element engaging said toggle, the other end engaging another of said toggles along the length of said apparatus, spaces between the elements of one series not contiguous with spaces between elements of the other series, said series being adjacent each other, said rod having portions of different thickness Ialong its length, said springs urging i said extensible member into contact with said toggles and said toggles into contact with said rod, and resiliently actuated releasable locking means between said rod and said frame.

2. Apparatus as in claim 1 wherein the extensible and retractable means comprise two series of interdigitating elements, the members of the first of said series each comprising two spaced-apart elements with their outer surfaces curved to match the inner surface of the tubing, Sald elements being joined by a bridging element therebetween, the second series of elements comprising a sealing element with the same curvature as the sealing elernents of said first series and a cantilever member extending longitudinally thereof, and wherein the cantilever element of the second series and the bridging element of the first series have the same transverse cross section, wherein the thickness of each of the sealing members exceeds the distance between the inner wall of the tubing and the outer diameter of the frame.

3. An expansible piston for reciprocal travel within an oil well tubing and comprising a frame subassembly, an expansible sealing subassembly, and a control subassembly, said frame subassembly comprising a thin bridging portion joined at its ends to a thick upper end and a thick lower end of a cylindrical longitudinally extending body, a cylindrical cavity extending from one end of a longitudinally extending body to the other and said cavity being coaxial with said body, said body being a maximum external diameter substantially less than the internal diameter of said tubing, said sealing subassembly being located radially peripheral to said bridging portion and extending from said body lower end to said body upper end and being reversibly and resiliently expansible from the maximum diameter of said body to a predetermined diameter at least as great as the diameter of said tubing, said sealing subassembly comprising a plurality of set of similar sealing elements each of said elements extending longitudinally of said body and being movable radially thereof, a spring extending between said bridging element of said body and each member of at least one set of said similar sealing elements and urging each said member radially outward from said bridging element, said bridging element to said sealing element and resiliently urging said sealing element outwardly against the interior of said tubing wall when said sealing subassembly is in its expanded position in said tubing, the control subassembly comprising a contoured control rod, levers actuated by said rod, and a rod holding means, said control rod being a longitudinally etxending cylindrical shaft which extends through the cavity in the frame subassembly and having a central longitudinal axis coaxial with the central longitudinal axis of the frame body, said shaft having a length greater than the length of said frame subassembly, levers pivotally mounted on said frame subassernbly, each of said levers being of the same size and shape and each of said levers being pivotally mounted on said frame subassembly for rotation in a plane parallel to the central longitudinal axis of the rod, all of said levers being pivotally mounted at the same distance from said axis, each of said levers having a follower portion that contacts the rod, and another end of each of said levers longitudinally overlapping and extending radially peripherally of one longitudinal end of one of said sealing elements and another of said levers longitudinally distant therefrom extending radially peripherally of and longitudinally overlapping the opposite longitudinal end of said same sealing element, said sealing element having a portion thereof which extends radially peripherally of a member of a set of sealing elements to which a spring is attached, said lever elements at the ends of said same sealing element, in the contracted position of the sealing subassembly holding said sealing element radially inward, and said sealing element contacting and moving radially inward an adjacent sealing element of said other set of sealing elements of which adjacent sealing element a narrow longitudinally extending portion underlies a wide portion of said sealing element overlapped by said lever elements, and rod holding means comprising movable locking means held in part in said rod and in part in said frame subassembly, and means urging said locking means to and in a position locking said rod and frame.

4. An expansible piston providing for external by-pass of fluid on reciprocal travel within an oil well tubing and comprising a frame subassembly, an expansible sealing subassembly, and a control subassembly, said frame subassembly comprising a longitudinally extending cylindrical body, one upper end thereof formed with a lishing neck and head, and a central subassembly holding means supported in said upper end, said upper end joined `to at its lower end to the upper end of a cylindrical longitudinally extending bridging portion of uniform diameter, said diameter being smaller than the diameter of said upper end, said bridging portion joined at its lower end to the upper end of the expanded lower end of said body,

14 said lower end having a diameterof the same size as the upper end of said body, all portions of said body being coaxial with each other, a cylindrical cavity extending from one end of said longitudinally extending body to the other and said cavity 'being coaxial with said body, said body being a maximum external diameter substantially less than the internal diameter of said tubing, said sealing subassembly being located radially peripheral to said bridging portion and extending from said body upper end to said body lower end and being reversibly and resiliently expansible from the maximum diameter of -said body upper end to a predetermined diameter at least as great as the diameter of said tubing, said sealing subassembly comprising a plurality of sets of similar sealing elements and springs therefor each element extending longitudinally of said body and movable radially thereof, each of said sealing elements having' a radially peripheral exterior surface tting the interior surface of said tubing and each of said sealing elements having a maximum thickness measured in the radial direction of said tool equal to the difference in diameter of said body bridging portion and the maximum diameter of said lower end of said body, one set of said sealing elements wherein each of said elements comprises a central radially peripheral and peripherally curved Wide sealing surface and a pair lof narrower centrally located arms forwardly and rearwardly extending therefrom, another set of said sealing elements wherein each of said elements comprises two spaced apart radially peripheral wide and peripherally curved sealing surfaces joined by a narrower centrally located arm therebetween, a spring extending between said bridging element of said body and each member of at least one set of said similar sealing elements and urging each said member radially outward from said bridging element, a seat for said spring in said bridging element and a seat for said spring member in said sealing member, each said spring extending from its seat in said bridging element to said seat in said sealing element and resiliently urging said sealing element outwardly against the interior of said tubing wall when said sealing subassembly is in its expanded position in said tubing, the control subassembly comprising a contoured control rod, levers actuated by said rod, and a rod holding means, said control rod being a longitudinally extending cylindrical shaft which extends through the cavity in the frame subassembly and having a central longitudinal axis coaxial with the central longitudinal axis of the frame tbody, said shaft having a length greater than the length of Said frame subassembly, one end of said rod projecting from the top end of said frame subassembly in the expanded position of the sealing subassembly'and the other end thereof projecting from the bottom end of said frame subassembly in the contracted position of said sealing subassembly, said rod having two portions of reduced exterior cross-section located within the frame subassembly and a smooth surface at an angle to the axis lof said rod joining each of said portions of reduced cross section to the remainder of said rod, said surfaces at an angle having the same shape and direction, a plurality of levers each pivotally mounted on said frame subassembly, each of said levers being of the same size and shape and each of said levers being pivotally mounted on said frame subassembly for rotation in a plane parallel to the central longitudinal axis of the control rod, all of said levers being located at the same distance from said axis, each of said levers having a follower portion that contacts the control rod in the neighborhood of a smooth angled surface thereof joining to a portion of reduced cross section thereof, and another end of each of said levers longitudinally overlapping and extending radially peripherally of one longitudinal end of one of said sealing elements and another of said levers longitudinally distant therefrom extending radially peripherv .ally of and longitudinally overlapping the opposite longitudinal end of said same sealing element, said sealing element having a portion thereof which extends radailly peripherally of a member of a set of sealing elements to which a spring is attached, said lever elements at the ends of said same sealing element, in the contracted position of the sealing subassembly holding said sealing element radially inward, and said sealing element contacting and moving radially inward, an adjacent sealing element of said other set of sealing elements of which adjacent sealing element a narrow longitudinally extending portion underlies a wide portion of said sealing element overlapped by said lever elements, and rod holding means 10 comprising movable locking means held in part in said rod and in part in said frame subassembly, and resilient means contacting said locking means and resiliently yet releasably urging said locking means to and in a position locking said rod and frame together.

References Cited by the Examiner UNITED STATES PATENTS 2,674,951 4/1954 Zaba 103-52 2,684,633 7/1954 Knox 103-52 2,762,310 9/ 1956 Eklund lO3.-52

ROBERT M. WALKER, Primary Examiner.

Claims

1. AN OIL WELL APPARATUS PROVIDING FOR AN EXTERNAL BYPASS OF FLUID THEREPAST FOR OPERATION IN A WELL TUBING COMPRISING A FRAME WITH A LONGITUDINALLY EXTENDING RECESS THERETHROUGH, ROD HOLDING MEANS IN SAID FRAME, SAID ROD BEING SLIDABLY HELD IN SAID RECESS IN ONE OF TWO POSITIONS, TOGGLE MEANS ACTUATED BY SAID ROD AND PIVOTALLY ATTACHED TO SAID FRAME FOR MOTION OF ONE PORTION THEREOF INWARD AND OUTWARD ON UPWARD AND DOWNWARD MOTION OF THE ROD WITH RESPECT TO SAID FRAME, TWO SERIES OF SEALING ELEMENTS EACH OF WHICH SERIES CIRCUMSCRIBE THE PERIPHERY OF SAID FRAME, EACH OF THE ELEMENTS OF AT LEAST ONE OF SAID SERIES HAVING A SPRING NESTED THEREIN AND SAID SPRING PRESSING EACH OF SAID ELEMENT OUTWARD, ONE EDGE OF ONE PORTION OF SAID ELEMENT ENGAGING SAID TOGGLE, THE OTHER END ENGAGING ANOTHER OF SAID TOGGLES ALONG THE LENGTH OF SAID APPARATUS, SPACES BETWEEN THE ELEMENTS OF ONE SERIES NOT CONTIGUOUS WITH SPACES BETWEEN ELEMENTS OF THE OTHER SERIES, SAID SERIES BEING ADJACENT EACH OTHER, SAID ROD HAVING PORTIONS OF DIFFERENT THICKNESS ALONG ITS LENGTH, SAID SPRINGS URGING SAID EXTENSIBLE MEMBER INTO CONTACT WITH SAID TOGGLES AND SAID TOGGLES INTO CONTACT WITH SAID ROD, AND RESILIENTLY ACTUATED RELEASABLE LOCKING MEANS BETWEEN SAID ROD AND SAID FRAME.