US2287205A - Packing head - Google Patents

Description

June 3. 1942.

STONE PACKING HEAD 9 Sheets-Sheet 1 Filed Jan. 27, 19

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IIIIMWIMFIHIHI M MQ Wu HHHHUMHU June23, 1942. STQNE 2 ,287,205

PACKING HEAD I Filed Jan. 27, 1939 9 Sheets-Sheet 2 Jive/liar Stone.

June 23, 1942. STQNE Q 2,287,205

PACKING HEAD Filed Jan. 27, 1939 9 Sheets-sheaf s 51 diwmy June 23, 1942. F, STONE 'PACKING HEAD Filed Jan. 27, 1939 I 9 Sheets-Sheet 4 .Zizzenfvr fiedelz'a? 520226.

(MUM b 7 0 9 /0 W M ix a Ju r xe 23,3942. F. STONE 2,287,205

PACKING HEAD Filed Jan. 27, 1939 9 Sheets-Sheet 6 June 23, 1942. STQNE I 2,287,205

PACKING HEAD Filed Jan. 27, 1939 9 Sheets-Sheet '7 2/ Inventor l'rederivk 5102a.

F. STONE (PACKING HEAD June 23, 1942.

9 Sheets-Sheet 8 Filed Jan. 27, 1939 June 23, 1942. F STONE 2,287,205

PACKING HEAD Filed Jan. 27, 1939 9 Sheets-Sheet 9 Patented .Fune 23, 1942 g PACKING HEAD Frederick Stone, Redondo Beach, Calif.,.assignor to Hydril Company of California, Los Angelcs,

' Calii'., a corporation of California ApplicationJanuary 27. 1939, Serial it... 253.10g

g 21 Claims.

This invention has to do generally with oil well packing heads used for such purposes as sealing around drill pipe or other work extending from the well into the head. It may be used for maintaining constantly a seal about drill pipe as it is being rotated or moved vertically through the head during pressure drilling,-or may be utilized as a blow-out preventer, in which latter case it normally stands in idle condition but is effective to be brought into play, either automatically or by manually controlled actuating forces.-

to effect a seal about the workand thus prevent the well from blowing out. It will be seen that irrespective of its particular use, whether that use be one of those mentioned above or any other use to which it is suited, the device may be characterized generally as a packing head.

In certain aspects, the invention may be con-,

sidered as an improvement over the devices shown in the following patents: Patents No. 2,038,140 issued to Frederick Stone April 21, 1936; No. 2,124,015 issued to Frederick Stone et al.-on July 19, 1938, both on Packing heads; No. 2,163,813 issued to Frederick Stone et al. June 2'7, 1939, fora Well packifi? head; and No. 2,148,844

issued Feb. 28, 1939 to Albert L. Stone et al. on i t u t welbpressure inlet valve shown in Packing heads for oil wells.

'ternal source of operating fluid; Fig. 2 is an enlarged, fragmentary section posed on and very serious duties are intended to be performed by a device of this type and when the time comes for it to go into operation, failure or delay may easily result in loss of life and property, or cause such damage that a well may have to be abandoned or made subject to costly repair operations. I

The various means employed for giving the device great working range and rendering it swift, sure, and durable in operation, may be discussed to better advantage in connection with the following detailed description, wherein reference is made to the accompanying drawings, in which:

Fig. 1 is a side elevation'of a head embodying 1 my invention, showing it in association witha conventionally illustrated rotary table and an extaken on line 2-2 of Fig. 1;

It. is among the objects of the invention to provide a packing head which, in spite of the fact.

that it has suflicient diametrical capacity to take work of relatively great diameter, is likewise effective to seal oil Work of relatively small diameter,

it following that the single head is, within reasonable limits; adapted to accommodate all the elements of a given string of drilling tools from the relatively small-diameter drill pipe, proper, through the various collars and upsets and through the relatively large drill collar and, in

certain cases, thetool at the lower end of the string. The advantage of such capacity is obvious. I

The head is also of such character that it gives the operator ready access to the various internal parts for inspection, repair, or replacement, it being possible to remove relatively rapidly wearing parts as the packer, proper, without disassembling the rest of the head and by working entirely through the bore of the rotary table overlying the head. i The importance of this feature is readily recognizable by those working in the art.

1 It is also an important object of the invention to provide means whereby the operation ofthe head is safe, sure and rapid, for it will be recognized that very severe service strains are imline ll of Fig. 3;

Fig. 3 is a longitudinal section taken on line 3-3 of Fig. 4;

Fig. 4 is a top plan view of Fig. 3;

Fig. 5 is an enlarged section on line 55 Fig. 3;

Fig. 6 is an enlarged, fragmentarysection taken Fig. 3;

Fig. '1 is an enlarged fragmentary section on Fig. 8 is an enlarged section. on line 8.8 of Fig. 4:

Fig. 9 is a detached, fragmentary assembly of the segmental bushing, showing the individual segments or leaves in inoperative positions;

Fig. 10 is a view similar to Fig. 9.but showing the individual segments inoperative positions;

Fig. 11 is a top plan view of Fig. 10, but showing additionally the spring means tending normally to hold the segments yieldably in inoperative positions;

Fig. 12 is a view similar to'Fig.. 3 but showing the packer in=. cont racted condition, and showing the safety check valve in closed condition;

Fig. 13 is a. view similar to Fig. 3 but showing a different type of packer and packer bushing'in place;

Fig. 14 is an enlarged fragmentary section showing the bushing mounting of Fig/13;

Fig. 15 is a fragmentary section on line [5-15 or Fig. 14;

Fig. 16 is a view similar to Fig. 14 but showing the parts in different positions; J

Fig. 17 is an enlarged fragmentary section of the reinforced packer section shown in Fig. 13;

Fig. 18 is a detached view of onset the reinforcing inserts; and

Fig. 19 is a view similar to Fig. 13, but showing the packer in contracted condition.

table. The head is usually --disposed in the cellar".just below the table, it following that its internal parts are relatively inaccessible for inspection or replacement except through the table bore. This fact has been taken into account in Iashioning certain of the parts, as will later a ar.

l he body member or housing ii of head I! includes a barrel portion Ila having a major bore l4, 9. counterbore l5 internally threaded at l5, and a conical bore I! which inclines inwardly and downwardly to the lower and relatively reduced bore 18. The lower end of the housing is flanged at I! for connection at 28 with the upper flange of side-outlet spool 2i, Many other suitable fitting; the spool, in turn, being-secured at 22 to flange 28 of coupling 24. the latter being adapted to be connected directly or indirectly to the upper end of the well casing (not shown). The bore 25 of coupling 24 and the lower portion 26 of the spool bore are substantially the same size as'the bore of the casing to which a given head is to be applied, and it n'iay therefore be considered broadly that the coupling member and spool make up the upper end of thestrlng of casing. The upper portion 21 of the spool bore flares sufilciently to bring bore-defining wall 28 substantially flush with the defining wall of housin bore il,.while side outlet port 29 opens outwardly from the spool bore to flow control valve 88 (Fig. 1). I a

The joints between spool 2i and flanges I9 and 28 are packed oil as at 8| and 82, respectively, The lower end of housing flange I9 is chamfered about bore II as at 33 to define, with the upper face of the spool, an annular gr ve 34 which opens, in efiect, to the bores of the housing and spool. I

Vertically slidable within housing barrel "a is the tubular piston or packer-contracter gen-- erally indicated at 35, this member having. a

main piston portion or head 98 which has sliding fit within major bore l4, a reduced diameter piston portion or head 81 having sliding flt within bore ll and a connecting neck 88 extending between the piston heads and comprising an upper conical portion 99, a lower cylindrical portion 40. and an intermediate conical portion 4!, which latter has the same inclination as the face of body-wall 42 which defines body bore l1. The seating of portion 4! on the inner face of wall 42 limits the, downward movement of the piston or contractei'.

.6! and 52 (Fig. 6).

Though it will later be described in detail. it will suillce here to-state that packer P is in the nature of a resilient, radially contractible sleeve of rubber or the like extending within the contracter bore and so shaped that upward movement of the contracter radially movesitinto sealing engagement with work extending through the bore thereof (Fig.

Piston head 35 of contractor 35 is packed oflby annular rings 48, 44 and 45, these rings being preferably of rubber or the like and having V- shaped cross-section, the V's of rings 44 and 45 opening downwardly and the V of ring 43 opening upwardly. Piston head His packed oil by rings 49 and whichare of the same character as the upper rings, the V's of rings 43 and 4'! opening upwardly and downwardly, respectively. Both heads are thus packedbff against fluid pressure. directed either upwardly or downwardly between the peripheries of the heads and the bore-walls along which they are adapted to reciprocate; I

Defined between the lower end 48 of piston head 35 and neck portion 39 on the one hand and .ihe defining wall of bore H on the other hand, is an annular chamber 49; while defined between the upper end 58 of head 31 and piston-portions 40,-4i on the one hand and body-wall portion 5! on the other hand, is an annular chamber 52. However, wall portion 42 is preferably routed as at 59 to interconnect chambers 49 and 52 when the contractor is in its lowermost position (Fig. 3) and, when the contracter is elevated (Fig. 12)- chambers 49 and 52 are in full communication. so it may be considered that, in effect, chambers 49 and 52 make up a single chamber 54 for the reception of packer-setting fluid pressure, said single chamber being located between piston heads 88 and I1.

Contracter 35 thus presents within chamber 54 the downwardly exposed pressure-taking faces 48, 55 and 55, and upwardly presented pressuretaking face 50. Thelower end of the contracter 80 presents a downward face 51 to fluid under pressure within the spool and piston bores, while the upper end of piston head 86 presents an upwardly lacing shoulder 58 to 'chamber 68a defined within the upper end of housing l3, as will later be described. A passageway 59, which may be considered broadly as being within the packing head. extends through housing wall portions 42 and 5| from recess or groove 34, thus being constantly in communication with the bore of spool 2|, or, generally, with the bore of the housing or casing at a point below packer P. Passageway 59 opens to the transverse body-passage 50 which is normally in communication with chamber 49, or more broadly, chamber 54. Disposed in passageway 68 are the valves generally indicated at A cage "is threaded at 64 fined by the bore of seat ring 68 which is pressfitted incage-bore 81, the ring being peripherally notched as at 68 to provide bleed ports or minor orifices. The check valve ball or stopper 59 is loosely confined within cage 58, permitting the flowof fluid through passageways 59 and into chamber 54 through major orifice 85, but preventing substantial reverse flow.

Valve 52 comprises a shut-oil means for the bore-Ill of cage 58 and, comprises a stem ll suitably packed oflf at I2 and threaded through the bore of bushing 13, which latter is held within bore ill in the manner clearly shown. It will be seen that the stopper'end I4 of stem ll may be adjusted either to allow free passage ofwfluid between passageway 59 and cage-bore 10 or to close I 01! communication between said bores, in which latter case there may be no fluid flow through either the m jor or minor orifices of valve 6i.

relieve excess pressure within chambe 54.

I6 to piston head 81. A bore I8 in boss IG'c'ommunicates with the upper end of vertical passage 19 in boss 11, the lower end of passage 19 opening to the bore of the contracter below the packer. Bore 18 has an inlet 88 opening to chamber 54, this inlet being bounded by an internal seat 82' and the excess pressure will be relieved through inlet 88, passageway 18 and bore 19.

In addition to the previously described pasand the sliding port 98 which is screwed at 91 into bore 94 and is thus vertically adjustable. The lower end of bore 94 is closed by a removable plug 98 which,

when removed, gives access to the bore so a suit-.

able tool may be inserted in the polygonal socket 99 of ball support 98 for adjusting said member and hence stopper 93 vertically. Member 98 is adjusted in a manner to support a ball in the a position where it has the requisite sensitivity for sageways and valves for admitting fluid under pressure to chamber 54 from the bore of the housing or casing at a point below packer P, I provide means for introducing fluid under, pressure to that chamber from an external source. Such means is shown as including a pipe 85 and valve 88 (Fig. 1) the latter being put in communication with inlet passagewayt'l by nipple 88, though broadly, the bore 89 of the nipple may be considered as a part of the inlet. Portion a given condition. An average position is indicated'in Fig. 3 where the top of the ball barely extends above the lower defining walls of bores 89 and 98. "I'hen,'during normal flow through these bores, in either direction, ball 93 remains at rest in bore 94. If, however, the inlet pressure is suddenly reduced, there is a rapid flow of fluid from chamber 54 outwardly-through the inlet, the stopper being sucked" upwardly from bore 94 and into a position where it closes bore 89 by seating against the conical seat I88 formed at the inner end of the nipple, thus preventing further escape of fluid from chamber 54 and holding the contracter upwardly in packer-contracting position, the response of the ball being so rapid that practically no pressure is lost from space 54 before the ball is seated. Due to the spherical char- 98 of inlet 81 is in the form of a bore through the housing wall and opening to chamber 49 (or, more broadly, to chamber 54) bore 98 being of substantially the same diameter as the nipple bore, .while between the inner end of the nipple and the opposing end of bore portion 98 is an enlarged valve chamber 9!. Now it will later be made apparentthat inlet 97 is adapted to serve alternately to introduce fluid under pressure to chamber 54 for moving the contracter upwardly in order to radially contract packer P, and for exhausting that chamber in order thatthe contracter may move downwardly. It follows that the inlet must normally be in a condition to allow fluid flow therethrough in either direction. However, assuming that the contracter is being held upwardly in packer-contracting position (Fig. 12) by pressure admitted to space 54 from an external source, if pipe 85, valve 86 or any other part of the inlet line were accidentally broken. the contracter would, in the absence of preventative means, drop by reason of the relief of pressure from chamber 54. and the packer would thus be allowed to expand, resulting in the loss of the seal about the work, an occurrence which might easily be disastrous or, at least. would create an extremely hazardous condition. It might be assumed that an ordinary check valve to prevent this reverse flow could be utilized for safe-guarding against an occurrence, but that would not sufilce, for it must be remembered that reverse flow is essential when it is desired wilfully to exhaust space 54 when the time comes for moving the packer downwardly, and an ordinary check valve would prevent such normal reverseflow.

Accordingly, I have devised a valve which permits normal-flow of fluid in either direction through the inlet but, upon sudden reduction of the inlet pressure (as by breaking the inlet line). responds in a manner to check reverse or exhaust flow through the inlet.

The automatically selective check .valve devised for the above purpose is indicated generally at 92 and comprises a stopper 93, preferably, though not necessarily, spherical in form and mounted in a vertically extending bore 94 opening at its upper end to valve chamber 9|. The stopper is supported on extension 95 of plug or ball supacteristics of stopper 93, its movement into seated position is aided by the fact that theoutwardly rushing fluid tends to rotate it in a clockwise direction (Fig. 3) and thus tends to roll it up along the right-hand defining wall of bore 94.

It will be seen that by adjusting member 96 vertically and thus raising or lowering the ball with relation to inlet 81 and chamber 9!, thesensitivity of the valve may be varied at will. By removing plug 98, it will be seen that the valve may be adjusted from the exterior of the housing even though the interior of that housing be under pressure, for member 95 has such fit within bore 94 that there will be no appreciable loss by leakage even though plug 98 be removed.

Ball 93 is, of course, too large to permit its 7 bodily movement through either bore 89 or 98.

but to prevent the ball from ever reaching afp'o sition where it might check flow of fluid from bore 89 into chamber 54, I have provided a bypass l8l extending from chamber 9| into chamber 54, it being impossible for the ball to,close on both bore 98 and by-pass l8l at the same time.

It will later be made apparent that valve 62 is normally open but, when fluid from an external source is admitted through inlet ,8! to chamber 54, valve 6| will act as a check valve to prevent the fluid so introduced from escaping through passageway 59 to the housing bore below the packer, although bleed-ports 68 allow a very slow escape from the chamber through passage v 59 but not in sufficient volume to affect the operation so long as the input does not drop below a certain value.

Under the conditions outlined above, that is valve 92 closes the inlet by reason of a,

when break in the inlet line, and with check valve 8| closed by reason of the high' pressure within I chamber 54, were it not for bleed ports 88 or some equivalent provision. it would bepractically impossible under certain conditions'a'nd even after the repair to the inlet lines were'made, to unseat 88 prevent the existence of such a pressure'lock,

for the pressure within chamber. 54 will gradually be reduced by the outward 'flow through the bleed ports and passageway 58,.though not with a speed sufflcient to destroy the safety effect of valve 82. Of course, if, after valve 82 automatically closes, it be desired temporarily to prevent escape through the bleed ports so that full pressure may be held in chamber 54 until repairs have been made, it is merely necessary manually to close valve 52. Then, when it is desired subsequently to lower the contracter, it is merely necessary to open valve 82 and the pressure will gradually bleed out through ports 58 into the housing or casing bore below the packer, being thus disposed of controllably and safely.

Another situation wherein manually controlled sumcient to actuate the packer contracter and bottled gas is admitted for this purpose through inlet 81. and the capacity of the bottles" is relatively limited, it becomes a matter of economy to close valve 52 and thereby prevent the gas from escaping.

While it will be seen that by incorporating valve 82 within the body structure of the head, it is assured that the valve is 50 protected that it will always be in a condition to automatically said bore opening into neck bore I II which flares at its ,lower end I".

The major bore II8 of the packeris cylindrical, the packer being further provided with conivalve 52 is closed, is when well pressure is in- Since this gasis relatively expensive shut off the inlet if breakage occurs in the inlet line where it extends outwardly beyond the housing, I prefer to take additional precaution to protect valve 86 against dropping or and supported. The horizontal portion I02 of the bracket is sufllciently wide to extend outwardly over the valve and thus serve as an effective protector. 4

Valve 85 is normally left open throughout opk eration of the packer, being provided as an auxcal counterbore Illa, a cylindrical counterborev I I8, a larger, arcuate counterbore I20, and a still larger terminal counterbore I2I. An annular, flexible hanger I22 of fabric or the like, has-its lower end I23 embedded or molded in the upper end of preformed packer P and,.preferably, the packer is internally reenforced at I24 beneath counterbore I20.

I will now describe the means for suspending the packer within body or housing I3 and for supporting the upper end of the packer in such 7 a manner that said upper end is held-against vertical bodily movement with respect to the housing. Threaded into housing counterbore I5 is a cap ring I25 whose internal diameter is at least as great as the inside diameter of piston bore H4 and, by the same token, as the overall outside diameter of packer P. The ring is packed off at its upper and lower ends I26 and I21 as clearly illustrated, and, after proper vertical adjustment, is releasably held from rotation and hence from vertical movement with relation to housing body I3 by a locking bar I28 which" is detachably held to the ring by bolt I28 and extends into slot I30 defined between-lugs I3I on the top of the housing barrel (Figs. 3 and 4).

Threaded at I32 into th bore of ring I25 is an annular packer-supporting member or ring I33 whose major bore is--indicated at, I34, an intemally threaded counterbore being indicated at I35. counterbore I35 is adapted to take any suit- 1 able connection or adapter for supporting whatever apparatus may be desirable in a given installation; for instance, a tandem drilling-packer head (not shown) such as is disclosed in certain iliary, manually controlled means for closing off inlet 81 under certain circumstances.

Packer P has what may be termed generally as a downwardly pointing conical end, said end having two angles of taper, namely an upper taper I08 of relatively slow angle and a lower taper II 0 of relatively abrupt angle, this combination giving the combined beneficial result of reducing the extreme end of the packer in a manner to allow it to be readily deformable in the manner best-adapted to take a proper shape under radial contracting pressures, and of providing suilicient radially extending bulk above that extreme end '/to give the packer relatively longlie under conditions of severe internal wear,

nular, downwardly pointing lip II2 which is adapted to be spread radially outward to effect a seal .with the, wall oi the contracter in the event there is leakage'between the contracter and the lower endof the. packer. The tip of the packer preferably has a downwardly opening,

conical counterbore H3.

The upper portion II 4 of the contracter bore is complementary to the external configuration of the packer, the lower, tapering portion II5 of of the aforementionedpatents and applications.

Annular packing I38 provides a seal between rings I25 and I33. Hingedly connected at I3I- to bar I28, is a locking bolt I33 adapted to drop into a selected notch I38 provided on the upper end of ring I33 to releasably hold ring I38 from rotating with relation to ring I25, and thus releasably locking ring I33 in its position of vertical adjustment. The upper end of. ring I33 is also provided with tool-taking formations I40 whereby the cap may be threaded into or cut of its position of assembly with the rest of the packing head. Rings I25 and I33 may be considered as making up an annular, tWOf-Dfllt cap for housing-barrel I3a. I

Ring I33 has 9. depending neck III with external, left-hand threads I42 and an external, over-.

hanging flange I43.

Threadably connected to neck I is a clamping ring I44 having an in- 1 temal flange I45 and an external flange I48, the upper face of the latter preferably having annular clamping grooves I41. Ring I44 is releasably held by set-screw I48 againstv rotation with relation to ring I33. Clamping ring I48 is bolted at I 50 to flange I48, said ring I48 preferably having' clamping grooves IN. The upper end of hanger I22 is extended horizontally between flange m and ring us, being clamped tightly in amanner to prevent longitudinal separative movement between .ring I33 and thepacker. Clamping ring I48 has a; depending, annular skirt I52 which surrounds the hanger. but there is sufficientannular clearance I53 between the outer peripheral face of flange I48 and the inner peripheral face of skirt I52 to allow limited lat wall of barrel I 3a, an annular chamber 504:, the

effective cross-sectional area of which is substantially equal to the area of piston fac 58, though the chamber is enlarged at 50b where it overlies the stationary ring I49 and flange I43. Diametrically opposite passageways I55 and I55 open through the housing wall to chamber 50a, one of the passageways being closed as by a removable plug I51 and the other having a fitting I58 for connection with a fluid pressure line I59 (Fig. 1') Should it be desired to flush out chamber 50a, the fitting and plug are removed and flushing fluid is admitted through one passage- -way I55 or I51, being thence circulated through the chamber and then out through the opposite passageway.

Extended through cap ring I and projecting into chamber 5011, are adjusting screws I50 which provide adjustable, positive stops for limiting the upward movement of contracter 35, the lower ends of said screws being opposed to end 5801' the contracter. As has been described in detail in connection with the showing of certain of the aforementioned patents'and applications, screws I50 provide means for positively limiting the contracting movement of contracter irrespective of the pressure exerted thereupon by the actuating fluid, all to the advantageous ends spoken of in said prior disclosures. I

In order toprevent leakage from chamber a around the threads of the adjusting screws, the

lower ends of said screws are packed off as clear- 1y shown at H, the packings of all the screws being held from downward bodily displacement by retainer ring I52 bolted at I53 to the underside of cap ring"I25. As pointed out in my Patent No. 2,124,015, it is of advantage for the operator to have constant knowledge of the relative position of the contracter within the housing and from this be able to ascertain the instant condition of the packer as regardsthe extent of its radial contraction (which, of course, depends directly upon the extent to which the contracter has been raised.)

. In that patent, there is disclosed an indicating rod which is secured to and movable with a part of the piston assembly. In the present device I have shown an indicator which is not secured to the contracter and therefore which enables easier assembling of certain internal parts of the packing head. However, the fact that there is no positive connection between the indicator and the piston creates other problems for which I have provided the solution, as will be demonstrated.

Referring to Fig. 8, it will be seen that a vertical bore I55 in cap-ring I25 registers with bore I55 in retainer ring I52. Extending through these bores is an indicator rod I51 having an enlarged head I58, an external flange I59 and a tip I10 which is of somewhat reduced diameter with respect to head I58.

An abutment ring "I forms a stop for the end of compression spring I12 which acts against flange I59 in a manner tending to hold tip I10 therefore the rela- Assuming there be no appreciable pressure within chamber 50a, if the contracter now descends, spring I12 exerts its pressure against flange I59 in a manner to cause rod I51 to follow the contracter downwardly and thus exteriorly to indicate the new position of the contracter. However, if there be appreciable pressure within chamber 50a it is necessary to counteract the pressural eifect of the fluid on the downwardly exposed faces of the rod, since all upwardly facing shoulders on the rod exteriorly of the housing are exposed only to atmospheric pressure, and the consequent differential in eifective pressures would cause the rod always to remain at the top of its stroke irrespective of the position of the contracter.

To overcome this efiect, I provide an externally arranged cylinder 113, screwed into the upper end of bore I55, packing I14- being interposed between the closed, lower end of the cylinder and stop ring "I to prevent leakage of fluid past either the rod or the exterior of the cylinder where it is threaded into the cap-ring. An extension I15 of indicator rod I51 carries piston head I15 disposed within cylinder I13, and the rod below the piston has-a central bore I11 opening at its lower end throu'gh port I18 to bore I55 and therefore to chamber 50a. Bore I 11 opens at its upper end to a short, central bore I19 in extension I15, which bore I19 communicates through port I with the interior of cylinder I13 above 'head I15. Vent I8I opens to the atmosphere from the cylinder'at a point below the lowest stroke limit of head I15, while the upper end of the cylinder is closed by cap I82 and the packing rings I83. Indicator extension I15 extends through cap I82 and may either directly carry indicia I84 or it may be connected as at I85 to a member I85 adapted, in turn, to actuate a remotely positioned indicator (not shown) of any suitable type.

Upon the upstroke of contracter 35, rod I51 is pushed upwardly by end shoulder 58, and pressure built up in the-cylinder above piston I15 is relieved by passing into chamber 50a through port I80, passages I19I11 and port I18. 0n the other hand, upon descension of the contracter, fluid from within chamber 50a is transmitted through the rod-passageways and ports to mosphere, the indicator rod will be moved downwardly by the force of spring I12 and whatever overbalancing fluid pressure advantage is given by reason of-the. differential eifective areas mentioned. 0f course,- this differential need only be enough to have a balancing efiect, disregarding the effect of the spring, in which case the actualdownward movement is imparted to the indicator rod solely by the spring.

By reference'to Figs. 1 and 3, it will placing packer P, it is only necessary to swing bolt I38 clear of slot I39and unscrew supporting ring I33 from the bore of cap-ring I25, where upon the supporting ring and all the parts sus- I pended therefrom, including packer P, may be lifted, as one, clear of the packer head and with drawn vertically through table bore I2. Such removal or subsequent replacement of the packer and its s pporting structure may be accomplished be noted I that'should occasion arise for removing or re-' without disturbing contracter 35 or cap ring I25 in any way.

The outside diameter of contracter 35 is such that it will also pass through table bore I2, but the outside diameter of cap ring I25 is usually such that it may not be passed through the table bore. Accordingly, when occasion arises for removing or replacing contracter 35, locking bolt I29 is released, ring I25 is unscrewed from counterbore I5, raised to the position approximately represented in dotted lines in Fig. 1 and then shifted sidewise clear of head. I3, whereupon contracter 35 may be withdrawn vertically through table bore I2.

Thus, while the contracter and piston are capable of ready removal from a position above the table, (a feature of decided advantage as is well recognized by those working in the art) the outside diameter of the packer may be relatively .very large, giving the packer ample radially extending mass even though its bore i sufllciently large to take work of relatively large diameter.

It willbe noted that packer bore I I8, as well as bores I34 and H5 of necks MI and 38, respectively, is of substantially the same diameter as bore 25 of spool 2|, it-followlng that the packer and the packer-actuating means ar adapted to take and pack-off work up to and including anything that may be passedthrough the spool and the casing therebelow. However, when the work is of relatively small diameter (and in this connection it will be recognized that a single string of drilling tools may have portions which vary between relatively wide limits in diameter) it becomes desirable to provide a bushing for the bore of the packer, which bushing is radiallyatively extreme condition of its inwardly radial spread.

I have shown means for interchangeably supporting two different types of such bushings, both types being radially and resiliently contractible.

The type shown in Figs. 3 and 12 is made up of rigid units, to form, in their contracted condition, a rigid, conical bushing, while the type shown in Figs. 13 and 19 is made of substantially the same material as the main packer. As a further difference, the bushing shown in Fig. 3 has a normal internal diameter substantially the same as that of the normal internal diameter of the main packer, being, in effect, set in a counterbore at the upper end ofsaid packer; while in Fig. 13, the bushing extends into the main bore of thepacker and, in effect, normally reduces the effective, inside diameter of the mainpacker. throughout a portion of its extent.

Referring particularly to Figs. 3, 7 and 9 to ing angularly a sufficient distance about the'hubs to'hold them'against bodily displacement from ring I. Holding bushing I90 (when detachedfroni supporting ring I33) in loose assembly, is a split ring I91 extended throughhub-bores I98. Ring I95 has a flange I95. clamped between .the underface of ring-neck HI and flange I45,

rings I95 and I being held against relative rotation by dowels I99 (Fig. 7) which are removable only when the packer is disconnected from supporting member I33. It will be seen that, with supporting ring I33 detached from the packing head, bushing I90 may be freed bodily from that ring by removing clamping-ring I09, unscrewing ring I from neck Ill, and removing dowels I99.

On the outer side of each segment is a lllg 200 having an arcuate face I which is substantially concentric with the associated hubs I93, the upper face 202 of the lugs, which may be recessed for purposes of weight-reduction as at 203, being adapted normally to extend horizontally. The lugs stop short of the lower end of fingers I92, thus leaving exposed an outer, vertically extending pressure-taking face 204 at the end of each finger.

Between each pair of hubs on each segment. is a torsion spring, 205 threaded on split ring I91 and having one end 205 anchored in the segment and the opposite end 201 anchored in ring I95. These springs act yieldingly to hold the fingers normally .in vertical position (Figs. 3 and 9) the faces 202 engaging the underside of ring I to limit their outward swinging movement. When the segments hang in this position their side edges 208 are angularly spaced, but the segments have overlapping formations such as side lugs 209 fitting within recesses 2I0 of adjacent segments, so that as one segment is swung'in or out, its side lug imparts like movement to the adjacent segment, it following that the segmental ring symmetrically expands or contracts as a whole when oppositely directed radial forces are applied laterally against one or more fingers.

When the segments are swung inwardly sufiicounterbore II9 with their inner faces substantially fiush with or a little below the defining wall of packer bore IIO, with the lower portions of arcuate lugs 200 fitting within the complebeing seated in packer counterbore I2I and engagingthe underside of clamping ring I. It will be seen that the upper end of packer P is thus rigidly backed up by the lower end of skirt- I I52,'ring 2H, and bushing I90.

Before proceeding {to' the description of operation, I will describe the conventionally iIlustrated system for supplying actuating fluid to the packing head, though it is to be understood showing is not at all to be considered as limitative either as to fluid source, piping connections of the control system, or valve mem- Line 2I3 leads to valve- 2I5 which is here shown in position to introduce line-steam to the low pressure side 2I5 ofbooster 2. However, valve 2 I5 may be adjusted to by-pass the booster and thus putline 2I3 into direct communication with feed'line 2II through line 2I8, the

latter' being provided with a check valve 2I9.

The high pressure. side 220 of the booster is connected by line HI and through check valve 222 to line 2, the latter leading to valve 223 which is here shown in a position to put lines 2|! and 85 into communication and as opening line I59 from chamber 60a to the atmossaid packer about the work. The action is not tain typical situations, relative pressures and responsive actions of the packer head elements also be assumed that the well pressure is of such relatively low value that it is unnecessary for the packer to be set.

Under such conditions, valve 06 is open; valve 85 is closed and valve 223 such condition that chamber 60a .is vented to the atmosphere.

the free upward flow of the well fluid about the pipe under conditions of suddenly increased volume to build up sufflcient pressure within chamber 54 (via passageways 59, 60 and check valve 5|) to move the contracter upwardly and thus, due to the inward wedging effect on the conical end of the packer to radially contract ordinarily one of extreme suddenness but it will 'be seenthat, as the packer starts to contract,

it gradually further chokes down the free flow of fluid around the work and thus directs more and more of the fluid into chamber 54 and finally becomes effective to move the contracter to its limit, as determined by stops I60 and thus to effect the shut-off desired. This. relatively gradual shut-off is preferable to the sudden shutwhere the shock incident to sudden closures Valve 62 will be open, and since it is highly desirable that it be closed only under the unusual circumstances mentioned above, so that chamber 54 may normally be constantly in communication with the well bore at a point below the packer, I prefer to provide valve stem H with a removable control handle Ha which will be left in the custody of some one authorized person and thus prevent the inadvertent closing of the valve by an unauthorized person who may not understand the importance of leaving it open under all normal circumstances.

Though the lower end of the contracter is exposed to the pressure within the well, the pressural effect against this lower end is balanced off by reason of the well pressure communicated to chamber 54 and exerted downwardly against face 50, as well as the well pressure directed against the upwardly presented face of the contracter at a point just below the lower end of the packer. The well pressure directed against downwardly presented contracter faces 55 and 56 which define a portion of the top of chamber 54, is substantially balanced off by the inherent resistance of packer P todeformation from its normal condition (Fig. 3) and such well pressure as is directed against the bore defining wall thereof.

what restricts the packer bore and, in some instances such as spoken of in the aforemen- 'tioned patents and applications, that there may be provided above the packing. head a second member tending to close off the space around the work, there is sufiicient restriction against against high pressures may result disastrously to the shut-off mechanism.

It will thus be seen that the packing head is constantly in condition to function as an automatically operated blow-out preventer in the event of a sudden increase in well pressure. Since the line leading from the bore below the packer to the contracter actuating chamber is constantly open under all normal conditions and since this line is self-contained within the head so it is not exposed to external damaging forces, it will be seen that there is practically no chance, for it to fail in operation when the emergency arises.

Fig. 12 illustrates a typical condition of complete shut-off about work of relatively reduced diameter, showing also how the packer adapts itself to work of varying diameter. Here the drill stem is indicated as being of quite small diameter, and it will be seen that as the packer has been pressed radially inward it has acted against pressure faces 204 of the fingers in a manner to swing the segments inwardly to a position where the bushing is' in the form of a rigid, closed, conical ring, thus forming a back- The pressure within chamber 54 acts against downwardly presented face 48 in ing for the upper and inward portion of the packer so that it does not flow" excessively upwardly about the pipe and has a rigid backing of relatively small diameter so that the sealing effect of the packer about the relatively small work is just as effective as it is about the larger diameter of the work where there is need of much less radial displacement of the packer material. I I

With the packer thus set, there. sometimes arises a need for moving the work vertically and as larger portions of the work, such as tool joint T, pass through the packer, it is essential that the bushing yield outwardly toprevent damage to the packer or to the: bushing segments. Werev the fingers to be of rectilinear formation throughout, as distinguished from the partial arcuate formation given to them by lugs 200, the

pressure tending to hold them inwardly would be so great that they would tend to remain; in the" positions of Fig. 12 and thus sever the upper end of the packer which extends between the fingers and the work., However, the arcuate lugs act, in eifecnas at least partial counterbalancing means, for the pressures directed against the arcuate faces by the packer all resolve themselves .into forces directed radially with respect to the axis of hubs I83 and thusthe only forces resisting movement of the segments to their ex-v panded positions are those directed by'the packer against pressure faces 204. Thus, in spite of the fact that the fingers are sufllciently long to cause a material reduction in the boreof the bushing when they are swung inwardly, their resistance to return movement is not represented by a pressure face equal to the overall length of said fingers, the reduction being suflicient to insure that the fingers may be swung to expanded position by the passage of relatively large .work therethrough without causing damage.

With the packer in the condition of Fig. 12, and the work is being moved vertically therethrough, whenever a relative enlargement in the work reaches the packer there is a tendency to forcibly depress both the packer and the piston. This may result in the building up of excessive pressures within chamber 54, particularly if that chamber contains an accumulation of liquid from the well or feed lines. In the event such excess pressures are created, which obviously might re- I suit in bursting the head or the. connecting pressure lines, unloading valve acts to relieve the pressure .within chamber 54 in the manner previously described. The effective strength of the.

unloading valve spring may be varied by adjustment of plug 93 to set the valve so that it will yield under any chosen pressure.

When it is desired to release the packer, valve 85' is openedand valve 223 is adjusted to vent line 85 and hence chamber 54 to the atmosphere. Then, if chamber 60a, above the piston .be vented to the atmosphere or if pressure be applied thereto through line 2I1, the contracter will descend and all parts will return to the positions shown in Fig. 3. In. order to release the packer, ordinarily it is only necessary to vent both chambers 55a and 54 to the atmosphere, as the contracter will then ordinarily drop by gravity. However, if the contracter sticks, fluid pressure may be admitted .to chamber 50a through line I59 to drive it downwardly.

If it be desired to hasten the upward movement of the piston once it has been started up by fluid pressure introduced through passageway 59, or if it be desired to elevate the packer entirely independently of the well pressure, fluid pressure may be admitted to chamber 54 from line 2 through valves 223, 85', and 95, chamber 50a being vented, as before.

In Figs. 13,- 14, 15, 16 and 19, I have shown a.

different type of packer bushing. Here, the bushing is made up of a radially contractible, resilient sleeve 225 of rubber or the like, which is adapted to fit within the upper end of bore 225-of packer P. Ring I95 is here replaced by a filler ring 195, and ring 2| l 'is omitted. The

upper end of bushing 225 has a bead 221 into which projects the internal reenforcement 223. Bead 221 is taken between the inner peripheral face of ring 195' and the defining wall of annular recess 229 provided'at the lower end of suspension ring 230. .Ring 230 has a springpressed latch 23! projecting-to the outer peripheral surface thereof, while it also has an internally threaded counterbore 232. Lock-actuating sleeve 233 has a head 234. adapted to be threadably adjusted through counterbore 232, the upward movement of the sleeve with respect to the ring being limited by a collar 235 threaded into. ring 235 at 235. A spreading ring or cone 231 is welded about the upper end of sleeve 233 in Fig. 16. This will be'the'condition of the bushing-supporting assembly before it has been applied to the supporting ring I33.

Neck I of ring 133 has an internal annular groove 240 presenting an upward face 241, and

at intervals about this groove there are provided recesses 242, the inner walls of both' the groove and recesses inclining inwardly and upwardly from shoulder 2. in the condition of Fig. 16, it is dropped into the bore of neck I until groove 240 is reached by latch 23I which thereupon. springs outwardly over shoulder 24! to prevent further downward movement of the assembly. The assembly is then rotated until latch 23! springs into one of the recesses 242, the latch thereafter holding ring 230 against rotation with relation to ring' I33. At this time, locking ring 239 is opposite annular recess 245 in neck I. Sleeve 233 is then threaded downwardly which causes wedging or spreading cone 231 to spread lock ring 239 into recess 245, thus tightly locking the bushing and its supporting assembly against longitudinal movement with relation 'to ring I33.

When the bushing is to be removed, ring 233 is unscrewed until the locking ring 245 is free to spring back'to the position of Fig. 16 and clear of groove 245. The bushing may then be lifted clear, since the inclined walls of recess 242 will cam latch 23l back to retracted position.

Fig. 19 illustrates the condition of bushing 225 when it is contracted about the work, which is here shown as consisting of drill stem 8. drill collar U and intermediate enlargement W. Packer P is shown as contracted about collar U, while bushing 225 is shown as adapting itself to pack off both stem S and enlargement W. If

it be desired to pull the work clear of the packing, as soon as the workshoulder Y strikes the lower end of bushing 225, locking ring 239 is released as described above and, as the work is elevated, shoulder Y pushes the bushing ahead of it and clear of the bore of packer P, but it will be observed that the packer P' will still continue to hold its seal about collar U in spite of the fact described in connection with the other figuresof and is provided with tool-taking formations 235.-

Split locking ring 239 has an inherent tendency to spring radially inward to release position, such inward movement being allowable when sleeve 2331s screwed to its upper limit, as indicated the drawings.

as apart of that packer.

As an added feature, however, I have provided means for preventing undue deformation of the lower end of packer P. This means is indicated generally at 250 but while it is here shown as being separable from the packer proper, as a matter of fact it may be considered consisting of a ring 25; made up of material similar to that of the main portion of the packer and extending upwardly into an annular groove- 252'provided in the lower end of main packer portion 253.

Moulded into 'ring 25l are segmental, rigid inserts 254 which are angularly'spaced apart to provide slots 255. The inserts have cavities or bores 255 into which the ring material is mo'ulded to act as retaining keys. The inserts have outer conical faces 251 which are adapted to slide on the opposed conical face of the contracter, while they have conical faces 253 presented toward the work. The spacing between the rigid inserts allows limited radial contraction of ring, 25!, as a whole, but never to a point where it is With the bushing assembly It is here shown as of suiiiciently reduced diameter to be movable into neck-bore H6.

The relatively resilient ring with its relatively rigid inserts is thus adapted to serve as a radially contractible bushing for the lower end of the packer, preventing that lower end from "flowing downwardly under extreme pressural conditions, to an undesirable extent. radially backs up the reduced-diameter tip of the packer so as to insure efiective sealing engagement with the work as clearly illustrated in 1. In a packing head for well pipe, a tubular housing adapted to take elongated work through its bore, a radially contractible packer in the housing and adapted to encircle the work, there being a space within the housing and an inlet for introducing fluid under pressure to said space, an increase in the fluid pressure within the space being effective to contract the packer radially about the work, and a safety valve adapted normally to permit flow of fluid through the valve and inlet to and from said space, said valve being adapted to close the inlet by virtue of a sudden reduction of inlet pressure to preventcontinued flow of fluid from said space through the inlet.

2. In a packing head for well pipe, a tubular housing adapted to take elongated work through its bore, a radially contractible packer in the housing and adapted to encircle the work, there being a space within the housing and an inlet for introducing fluid under pressure to said space, an increase in the fluid pressure within the space being eflective to contract the packer radially about the work, a safety valve adapted normally to permit flow of fluid through the valve and inlet to and from said space, said valve being adapted to close the inlet by virtue of a sudden reduction of inlet pressure to prevent continued" flow of fluid from said space through the inlet, and means for adjusting the sensitivity of said valve.

3. In a packing head for' well pipe, a tubular housing adapted to take elongated work through its bore, a radially contractible packer in the housing and adapted to encircle the work, there being a space within-the housing and an inlet for introducing fluid under pressure to said space, an increase in the fluid pressure within-the space being eilective to contract the packer radially about the work, and a safety valve adapted normally to permit flow of fluid through the inlet passageway to and from said space, said valve being adapted to close the inlet by virtue of a sud-' position of normal support ontosaid seat to close the passageway by virtue of an outrush of fluid from the space through the passageway.

4. In a packing head for 'well pipe, a tubular housing adapted to take elongated work through 'its bore, a radially contractible packer in the housing and adapted to encircle the work, a

Yet it housing adapted to take elongated work through packer contracter movable upwardly within said housing to contract the packer radially about such work, there being a substantially horizontal inlet passageway for introducing fluid under pressure to a space within the. housing and against the contracter in a manner to move it upwardly, an annular seat about the inlet passageway intermediate its ends and facing to: wards said space, a vertically extending recess opening at its upper end to said passageway between said space and the seat, and a ball stopper normally loosely mounted in said recess. 5. In a packing head for well pipe, a tubular housing adapted to take elongated work through its bore, a radially contractible packer in the housing and adapted to encircle the work, there being a space within the housing and an inlet for introducing fluid under pressure to said space, an increase in the fluid pressure within the space being effective to contract the packer radially about the work, and safety valve means adapted normally to permit flowof fluid through I the inlet passageway to and from the space, said valve meansbcing adapted to close the passageway by virtue ofa sudden reduction of inlet pressure to prevent continued flow of fluid from the space through the inlet, said valve means embodying a seat in the passageway and facing the space, and a stopper normally loosely supported at one side of the passageway and between the space and seat, said stopper being free for bodily movement from its position of normal support onto said seat to close the passageway by virtue of an outrush of fluid from the space through the passageway, and means insuring free flow' of fluidbetween the seat and the space should the valve stopper become lodged in the inlet passageway at a point removed from said seat,

6. In a packing head for well pipe, a tubular its bore, a radially contractible packer in the housing and adapted to encircle the work, there being a space within thehousing and an inlet for introducing fluid under pressure to 'said space, an increase in the fluid pressure'withinj the space being efiective to contract the packer radially about the work, and a safety valve adapted normally to permit flow of fluid through the valve and inlet to and from said space, said valve being adapted to close and thereby shut oil the inlet by virtue of a sudden reduction of inlet pressure to prevent continued flow of fluid from said space through the inlet, there being thework, valve means for controlling fluid flow a port leading from said space for bleeding fluid therefrom to provide for subsequently opening the valve.

7. In apac'kiz-ig head for well pipe, a tubular housing adapted to take elongated work through its bore, there being a space within the housing, a radially contractible'packer inthe space and adapted to encircle the work, there being a pasl sageway extending upwardly through the wall of the housing from the bore of the housing below the packer to said space for introducing well fluid from beneath the packer to said space in a manner'to contract the packer radially about through said passageway, there being an inlet for introducing fluid under pressure to said space from an external source, and a safety valve adapted normally to permit flow of fluid through the safety valve and inlet to and from said space, said safety valve .being adapted to close the inlet by virtue of a sudden reduction of inlet pressure,

through said inlet to prevent continued flow of fluid flow from the space through said inlet.

8. In a packing head for well pipe, a tubular upwardly, means for moving the contracter downwardly, there being a passageway in the spring-loaded valve in said contracter-passageway adapted to open automatically when the pressure in the space exceeds a given value.

9. In a packing head for well pipe, a tubular housing adapted to take elongated work through contracter opening downwardly from said space to the housing bore below the packer, and a contracter, a packer mounting ring detachably secured to the cap ring, and a radially contractible packer'suspended from s d mounting ring and adapted to be taken in he bore of the contracter, said packer being movable vertically through the bore of the cap-ring into or out of the contracter-bore without detaching said cap ring from the housing, during assembly or disassembly.

12. In a packing head for well pipe, a tubular housing adapted to take elongated work through its bore, a packer-supporting member supported within the housing a tubular radially contractible packer supported by saidmember, a bushing for the packer bore and supported by said member, and a packer contracter movable vertically through the housing bore, said bushing being characterized as a plurality of relatively its bore, a radially contracti ble packer in the housing and adapted to encircle the work, a packer contracter movable upwardly within said housing to contract the packer radially about such work, means for introducingfluid under pressure to a space within the housing and against the contracter in a manner to move it upwardly, means for moving the contracter downwardly, and an unloading valve acting automatically to open said space to the housing bore below the packer when the pressure in the space exceeds a given value.

.10. In a packing head for well pipe a tubular housing adapted-to take elongated work through vertically through the housing bore, the upper end of the housing bore being of a diameter to allow the contractor to be moved vertically therethrough during assembly and disassembly, a cap ring detachablysecured in the housing bore 'at the upper end thereof and directly overvlying the contracter, the inside diameter of the ring being at least as large as the maximum efiective diameter of the upper end of the contracter bore, and the lower face of the ring being spaced above the upper end of the contracter whereby a chamber is verticallydefined between that lower face and the upper end of the contracter, a packer mounting ring detachably se-- cured to the cap ring, and a radially contractible packer suspended from said mounting ring and adapted to be taken in the bore of the contracter, said packed being movable vertically through the bore of the cap-ring into or out of the contracter-bore without detaching said cap or ring from the housing, duringassembly or disassembly.

11. In a packing head for well pipe, a tubular housing adapted to take elongated work through its bore, a tubular packer-contracter slidable vertically through the housing bore, the upper end of the housing bore being of a diameter to its'bore, a tubular packer-contracter slidable rigid segments pivotally. supported at their upper ends by said member, said segments embodying fingers adapted normally to hang vertically with their side edges in angularly spaced relation and being pivotally m jvable toward the housing-bore axis until their side'edges engage one another to present, as an assembly, a; closed ring, the

outer faces of said fingers having projecting counterbalancing formations.

13. In a packing head for well pipe, a tubular housing adapted to take elongated work through its bore, a packer-supporting member supported within the housing, a tubular radially contractible packer supported by said member, a

axis until their side edges engage one another to 1' present, as an assembly, a closed ring, and arcubushing for the packer bore and supported by said member, and a packer contracter movable vertically through the housing bore, said bushing being characterized as a plurality of relatively rigid segments pivotally supported at their upper ends bysaid member, said segments embodying fingers adapted normally to hang vertically with their side edges in angularly spaced relation and being pivotally movable toward the housing-bore ate, convex formations on the outer faces of the fingers concentric with the pivotal axis of the --segments and extending from a point near their allow the contracter to be moved vertically i therethrough during assembly and disassembly, a cap ring detachably secured in the housing bore at the upper end thereof and directly overlying ,the contracter, the inside -maximum effective a chamber is vertically defined above the contracter, a vertically adjistable stop carried by the cap ring and extending downwardly into said chamber to limit the upward movement of said upper ends to a point spaced above their lower ends;

14. In a packing head for well pipe, a tubular housing adapted to take elongated work through its bore, a packer-supporting member supported within the housing, a tubular radially contractible packer supported by said member, a bushing for the packer bore and supported by said member, and a packe'r contracter movable vertically through the housing bore, said bushing being characterized as a plurality of relatively rigid segments pivotally supported at their upper ends by said member, said segments embodying fingers adapted normally to hang vertically with their side edges in angularly spaced relation' and being pivotally movable toward the housing-bore axis until their side edges engage one another to present, as an assembly, a closed ring, arcuate, convex formations on the outer faces of the fingers concentric with the pivotal their lower ends, and a relatively rigid ring at the upper end of the packer having a concave'arcuate face concentric with said pivotal axis and over which said convex formations are adapted to pass during pivotal movement of the fingers.

' 15. In a packing head for well pipe, a verti-" 1 cally arranged tubular housing adapted to take elongated work through its bore, an annular packer-supporting member coaxial with and supported within the housing, a tubular radially contractible packer coaxial with and supported by said member, a bushing for the packer bore and .supported by said member, and a pack'er contracter movable vertically through the housing bore, said bushing being characterized as a radially contractible sleeve of resilient material having its lower end-face exposed; a relatively a through its bore, a radially contractible packer sleeve in the housing and adapted to encircle the work, means supporting the upper end of the packer sleeve from the housing, angularly spaced, relatively rigid inserts carried at the lower end of the packer sleeve and having surfaces exteriorly exposed, each of said inserts havingftwo such exposed surfaces, one facing toward the bore of the sleeve and the other facing toward the outer. periphery of the sleeve, and a packer contracter movable upwardly within the housing against the lower end of the packer sleeve and against the inserts to contract said packer sleeve radially. a

17. In a packing head for well pipe, a vertically arranged tubular housing adapted to take elongated work through its bore, a tubular, radially contractible packer coaxial with and within the housing, an annular supporting member supported within the'housing, a radially contractible bushing, of resilient material, for the packer bore, and means releasably holding the bushing against longitudinal displacement through its bore, a radially contractible packer in the housing and adapted to encircle the work, there being a space within the housing and an inlet for introducing fluid under pressure to said space, an increase in the fluid pressure within the space being effective to contract the packer radially about the work, a safety valve adapted normally to permit flow of fluid through the valve and inlet to and from said space, said valve being adapted to close and thereby shut off the inlet by virtue of a sudden reduction of housing, a radially contractible packer in the space and adapted to encircle the work, there being a passageway extending from the bore of the housing below the packer to said space for introducing well fluid from beneath the packer to said space in a manner to contract the packer radially about the work, a check valve in said passageway for checking reverse flow therethrough, there being an inlet for introducing fluid under pressure to said space from an external source, and a safety valve adapted normally to permit flow of fluid through the safety valve and inlet to and from said spacefsaid safety valve being adapted to close the inlet by virtue of a sudden reduction of inlet'pressure through said inlet to prevent continued flow of fluid flow from the space through said inlet.

20. In a packing head for well pipe, a vertically arranged tubular housing adapted to take elongated work through its bore, a tubular packer coaxial with and within the housing, an annular '40 through the packer bore, said means embodying inlet pressure to prevent continued flow of fluid the valve. and manually controlled valve means for controlling fluid flow through said port.

19.In a packing head for well pipe, a tubu- .lar housing adapted to take elongated work through its bore, there being a. space within the supporting member supported by the housing, a bushing for the packer bore and having a rigid ring portion at its upper end, said portion being adapted to be taken within the bore of the annular supporting member, there being an annular recess in the bore-wall of the supporting member, a resilient, split locking ring carried by the ring portion and having an inherent spring tendency to contract radially toward release position, saidlocking ring lying in the-plane bf and being adapted to be. radially expanded into the recess and thus into locking position when the bushing is in operative position within the, packer bore, and an actuatingmember carried by the ring-portion and coacting with-the locking ring, said actuating member being movable to radially expand the locking ring into said recess. 21. In a packing head for well pipe, a vertically arranged tubular housing adapted to take elongated work through its bore, a tubular packer the plane of and being adapted to be radially o expanded into the recess and thus into lopkin position when the bushing is in operative position within the packer bore, the bore of the, looking ring tapering inwardly and downwardly, a downwardly and inwardly inclining cone carried by the ring-portion and threadably movable axially thereof and through the bore of the looking ring, said cone member being of a diameter to spread the locking ring radially into said recess when the cone is moved axially to a given position withinthe locking ring bore while the bushing is in operative position.

' FREDERICK STONE.

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