US2313576A - Core drilling device - Google Patents

Description

2 Sheets-Sheet l R. PHILLIPS ET AL CORE DRILLING DEVICE Filed May 6, 1940- Marsh 9, 1943.

`R. lA. PHILLIPS EIAL conf: DRILLING nEvIcE Filed may Y6. 194

2 Sheets-Sheet 2 w www uam 6 @am @@ayww M mm 1 5 7,1 a wi A z 56 y 5 a FM ww W 1@ 0, ge w Patented Mar.. 9, i943 entre oFFijcE 2,313,576 comi paname nevica Ralph A. Phillips, Hawthorne, and Mortimer L. Clopton, Glendale, Calif.

Application May 6, 1940, Serial No. 333,548

(Cl. Z55-2) 6 Claims.

Our invention relates to a core drilling device for use in taking cores in the drilling of wells and has particular reference to a means for controlling the circulation of drilling uid in and around the core carrier and to a means for registering the inclination of the Well at the point at which the core is taken.

In the drilling of deep wells, such as oil wells, by means of rotary drilling rigs it is common practice to periodically take cores to provide samples of the formation through which the well is being drilled. These cores are cut by means of a coring bit adapted to cut away the formation in an annular fashion so as to leave a core extending upwardly from the bottom of the hole. Such coring bits are equipped with an inner core barrel or core carrier fitted with core catchers adapted to break off the core and convey the same to the ground surface at the time the bit is removed from the wall.

In early coring bit constructions it was found that the core was badly broken and shattered as a result of the inner core barrel being rotated with the bit and relative to the core and as a result of excessive pressures developed on top of the core by virtue of the circulating fluid being entrapped between the top of the core and the closed upper end of the core barrel. Attempts to prevent such breaking and shattering of the cores led to the development of core taking devices wherein the inner core barrel was rotatably supported upon the coring bit so that the core barrel could remain stationary relative to the core, and also to the provision in the upper end of the core barrel of a. relief valve to permit iluid trapped above the core to be discharged as the inner barrel was gradually moved downwardly over the upstanding core.

vIt has been found that these expedients do not entirely solve the problem for the reason that during the time the bit is being initially lowered into the well bore preparatory to resuming a drilling operation, circulating iiuid contained within the well bore ows into the core barrel throughthe core receiving aperture which .is provided in the bottom of the coring bit. This drilling iluid is heavily laden with chips and fragments of stone dislodged by previous drilling operations so that when drilling is resumed these chips tend to wedge between the core and the core barrel to develop pressures tending to break the core. Furthermore, the chips get into the relief valve which is provided at the top of the core barrel and seriously impair the operation of that valve.

It is accordingly an object of our invention to provide a core drilling device which overcomes the above noted disadvantages.

It is an additional object of our invention to provided for preventing the flow of circulating.

iiuid through the core barrel begun.

It is also an object of our invention to provide an apparatus of the character set forth in the preceding paragraphs which includes a means normally permitting the circulation of drilling uid through the inner core barrel and which is actuatable from the ground surface to prevent such circulation through the inner core barrel.

It is a further object of our invention to provide an apparatus of the character set forth hereinbefore which includes a means responsive to iiow of circulating fluid through the drill string for iirst permitting such fluid to be circulated through the inner core barrel and then to later prevent such circulation.

In connection with the taking of cores it is highly desirable to know the inclination of the well from the vertical at the point from which the core was taken in order thatthe geological data obtained may be properly correlated. This infomation is at present obtained by means of separate inclination devices which may be either of the go-devil type introduced into the interior after the drilling is of the drill string and recovered by removal of the drill bit or of the wire line type which is lowered into the open hole and removed by means of a wire line. consume considerable time in their operation so that the drilling of the well iscorrespondingly delayed. Furthermore,4 there is always the attendant risk of losing these devices in the hole Y so as to entail an expensive fishing operation in connection with their recovery.

It is therefore an additional object of our invention to provide a core drilling device rof the character set forth hereinbefore which includes a means for ascertaining and registering the inclination of the well at the point where the core is taken to permit such inclination to be deter-1 mined at the time the core is removed from the well.

Both of these devices.

It is a still further object of our invention to provide a device of the character set forth in the preceding paragraph in which the device for registering the inclination is actuated in response to the starting of flow of circulation fluid through the drill string.

Other objects and advantages of our invention will be apparent from a study of the following specifications, read in connection with the accompanying drawings, wherein:

Fig. 1 is an elevation view of one form of core drilling device of our invention; I

Fig. 2 is a fragmentary longitudinal section of the device illustrated in Fig. l showing the interior construction and the relative disposition of parts at the time the device is being lowered into the well;

Fig. 3 is a view similar to Fig. 2 but illustrating the relative disposition of the parts at the time the device has been lowered to the bottom of the well but before drilling has been started;

Fig. 4 is also a view similar to Fig. 2 but illustrating the relative disposition of parts after the drilling operation is begun;

Fig. 5 is an enlarged longitudinal section of the mechanism illustrated in the upper portions of Figs. 2 through 4 and showing the parts thereof in the positions they occupy prior to the beginning of a drilling operation; and

Fig. 6 is a view similar to Fig 5 but illustrating the relative positions of the parts at the time the core is being taken.

Referring to the drawings, we have illustrated in Fig. 1 the preferred embodiment of our invention as including a coring bit head I which is attached by means of an adaptor 2 to a working barrel 3. The working barrel 3 may have secured to its upper end a pin half of a tool joint 4 to permit attachment to a drill collar or string of drill pipe by means of which the coring bit I may be rotated and urged downwardly to effect a drilling of the well. The engagement of the working barrel 3 with the `to`ol joint 4 may be effected by means of a threaded connection 4a and similarly the engagement of the working barrel 3 with the adaptor 2 may be by means of a threaded connection 4b.

As is clearly shown in Fig. 1 the coring bit I includes cutting elements 5 and 5 adapted to engage the .bottom of the hole and cut away the formation through which the well is being drilled. The bit I is provided with a central aperture 1 so that when the bit is rotated the cutters 5 and 6 will cut away the formation on an annular surface to denne a central core which will be received Within the aperture I as the bit gradually moves downward through the formation. As the core is thus move'd upwardly through the aperture 'I it is received within an inner core barrel 8, which inner barrel is preferably rotatably supported upon the coring bit so that it may remain stationary with respect to the core to reduce the liability of breaking the core off as the drilling progresses.

This mounting of the inner core barrel 8 may be readily effected as by securing the bit head I sleeve I as by means of screw threads I4, the cap member I3 being bored and threaded as indicated at I to receive a supporting spindle I8.

'I'he spindle I6 comprises a tubular member which carries on itslower end a radially out- Wardly extending flange above which is placed a ball thrust bearing I8 in encircling relation with the spindle I6, 'I'he upper end of the inner core barrel 8 is similarly fitted with a cap member I3 which may be attached thereto as by means of screw threads 20, the cap member I9 being provided withl a central aperture aidapted to loosely receive the spindle I6. Another ball thrust bearing 2I may be placed upon the spindle above the cap member I.9 and lock nuts 22 and 23 threadedly engaged with the spindle I8 may .be employed for clamping the cap member I9 between the thrust bearings I8 and 2| and for clamping these three elements securely against the flange portion Il of the spindle I8.

It will be seen that this structure operates to suspend the inner core barrel 8 from the upper end of the sleeve I0 and that such suspension permits rotation of the inner core barrel relative to the sleeve and relative to the working barrel 3 to which the inner sleeve I0 is attached by the intermediary of the adaptor 2. The lower end of the inner core barrel 8 may be held in axial alignment with the core receiving bore I which is provided in the bit I by providing an annular` seat 24 within the adaptor 2 and disposed below the aforementioned screw threads I2a vand by y adjusting the length of the inner core barrel 8 in such manner as to cause the lower end thereof to be rotatably received within the seat 24.

Our invention is directed to the provision of a means for controlling the circulation of drilling fluid through and around the inner core barrel 5. This control may be effected by means of a valve mechanism which is enclosed within a housing 25 which is secured to the cap member I3 through the intermediary of a valve seat member 28. The valve seat member 26 is preferably threadedly secured as by means of screw threads 21 to an upwardly projecting end of the spindle I8 and is itself exteriorly threaded so as to pro-` vide a threaded engagement 28 with the housing ing 25 of drilling uid which is circulated through to the adaptor 2 by means of screw threads 9 and c by extending upwardly from the adaptor 2 a sleeve I0 which is interposed between the inner core barrel 8 and the working barrel 3 so as to define annular spaces II and I2 on opposite sides of the sleeve I0, the sleeve I0 being secured to the adaptor 2 as by means of screw threads I2a. The sleeve I0 is provided with a cap member I3 which may be attached to the upper end of the a wash opening 29 provided in the drill string attached to the tool joint 4. The wash opening in the tool joint 4 is preferably adapted to closely receive the upper end 30 of the housing 25 so as to prevent the passage of drilling fluid between the housing and the tool joint and to insure that all of the fluid circulated through the wash opening 29 will be passed into the interior of the housing 25. The housing 25 preferably has an exterior diameter considerably smaller than the internal diameter of the working barrel 3 within which it is received so as to define an exterior annular space or circulating passage 3l between the housing 25 and the working barrel 3.

'I'he housing 25 supports a timing mechanism 32 which will be described in detail hereinafter. The timing mechanism 32 supports a valve member 33 adapted to be' urged downwardly by means of a spring 34 into engagement with a valve seat 35 formed in the upper edge surface of the valve seat member 25 and close 0E at this point the passage formed by the housing 25. 'I'he Valve 33 is supported from the timing mechanism 32 by means; ora; valve stem 'is which 'extends up wardly through the timing mechanism and carries on its upper end a latch member 31 adapted to be engaged by a pawl 38 which serves to hold `the valve 33 in an open position as illustrated in Fig. 2-against the closing force of the spring 3l. The pawl 38 is operatively connected as by means of a link 39 to a butterily 40 extended across the interior of the housing near its upper end. A plurality of fluid ports 4I communicating between the exterior and the interiorof the housing 25 are provided just below the butterfly 40 which is mounted for pivotal movenient between an upwardly inclined position,

such as that illustrated by dotted lines in Fig. 2, and a depressed position, such as that illustrated in Fig. 3,- the -location of the ports 4I being so adjusted as to permit the exposing of these ports to the upper portion of the iluid passage within thehousing 23 when the buttertly 40 is moved to the aforementioned depressed position. i

The link 33 is so engaged with the buttery Il as to cause a withdrawal of the pawl 38 from" the latch 31 when the buttery is moved to this depressed position, thus permitting the spring 34 to close the valve 33. The aforementioned timing mechanism 32 operates to interpose a time lapse between the release of the pawl 33f `of the bit I through the well bore and through the drilling fluid contained therein causes the drilling iluid to flow upwardly through the core receiving bore I in the manner indicated by arrows 42 in Fig. 2, this ilow continuing upwardly past the valve seat 35 and outwardly through row 43.

fluid ports 43 provided in the housing 25 just above the valve seat 35.

The ilow of drilling fluid is joined, as it discharges from the ports 3 3, with a similar i'iow of uid upwardly along the' iluid space I2 defined by the working barrel 3 and the sleeve I0, the fluid gaining access to this space through conventional wash openings 4I provided in the adaptor 2. This Huid ow is indicated in Fig. 2 by arrows 45. The combined flow of the 'fluid through the fluid space I2 and through the core receiving aperture I continues, as indicated in Fig. 2 by arrows 46, to the upper end of the working barrel 3 where, by virtue of the ports", an upward pressure is exerted on the butterfly l0 to swing this butterfly into its upward position as indicated by dotted lines in Fig. 2 to permit the'fiuid .to continue to flow upwardly through the wash opening 2S of the drill string. Attention is called to the fact that by thus providing for upward iluid flow through the drill string, the resistance to the lowering of the drill string into the well which might be caused by the drilling iluid remaining within the bore is effectively relieved.

Assoon as the bit has been lowered in the sagement with the bottom of the bore, the flow of circulating iluid past the butterfly 40 stops,

- that represented by the solid line position of the butteriiy 40 in Fig. 2.

It will be appreciated that the interior of the inner core barrel is', at this time, illled with drilling fluid containing a high percentage of rock .fragments and chips and that before drilling is commenced. it is highly desirable that this uid be washed out of the inner core barrel I and replaced by clean and fragment-free fluid supplied' from the slush pumps located at the ground surface. The slush pumps are accordingly started and the downward ow of clean drilling fluid through the circulating opening 29 is begun as indicated by arrow 41 in Fig. 3. This flow imposes a pressure upon the upper surface of the butterfly I0 to force the butterfly into its depressed position, as illustrated in Fig. 3, and

expose the ports 4I so as to permit the circulat.

ing fluid to pass from within the housing 2l into the fluid space 3| disposed exteriorly thereof, this iiow being indicated in Fig. 3 by the ar As pointed out hereinbefore, depression oi' the butterfly 40 releases the previously cocked valve 33 to permit it to begin its timed closing action. Prior to the actual closing of the valve 33, the downward iiow of the fluid alongside the housing 25 will continue so as to force a part of that uid to pass through the annular space I2 and outwardly through the wash opening M as indicated by arrow 49. The restriction which is ailorded by the wash opening 4l also causes a part of the drilling uid to pass through the l ports 43 and enter the interior oLthe housing 25 below the timing mechanism 32 as indicated by arrow 50 in Fig. 3.

This flow oi' the drilling fluid passes downwardly through the bore provided in the supporting; spindle I8 and into the inner core barrel l so as to displace the fluid previously contained in that inner core barrel as indicated by arrowsl 5I. This cleaning of the inner core barrel continues until after the aforementioned lapse of' time has transpired, at which -time. the valve. 33 closes andy seals oil? the passage into the inner core barrel which is aiorded up to that time by the ports 43, thus causing all of the iiow of circulating uid to thereafter be directed through the annular space I2 and outwardly through the wash openings 44 in the conventional manner.

`The positions occupied by the parts at the time the valve 33 is nally moved to its closed position.

is illustrated in Fig. 4. This is a position which is occupied by the parts during the time the.

bit I is being employed for the continued drilling of the well bore and for the production of a core sample to be taken by the bit. ence to Fig. 4 will show that as the bit progresses downwardly through the formation being drilled, the'core receiving aperture 1.' by virtue of the omission of cutting elements at that point, operates to leave an upstanding core 52 which, as the drilling progresses, moves upwardly relative to the inner core barrel I. This movement of the core 52 relative to the core barrel 3 must of a necessity displace from the inner core barrel the drilling fluid which is contained in the ulper portion thereof. This fluid may be readily discharged by providing near the upper end of the inner core barrel 8 a plurality oi ports I3 placed by the core 52 to be passed, vas indicated by arrows 54 in Fig. 4, into the annular space I I.

The uid may be discharged from the annular space II by means of auxiliary ports 55 which are formed in the body of the adaptor 2 and extended between the lower end of the annular space II and the aforementioned wash openings 44. The auxiliary ports 55 are preferably inclined in such manner as to intersect the wash openings 44 at a forwardly directed angle so that the high velocity flow of drilling fluid through the wash openings M operates to create a. suction in the auxiliary ports 55 by an injector action. 'I'his tends to further facilitate the removal of the drilling fluid which is contained between the top of the core 52 and the upper end of the inner core barrel 8 so as to insure against possibility of building up within the inner core barrel 8 any pressure which would inhibit the drilling of the well.

When drilling has progressed suiilciently to provide a core 52 of the desired length, the core is broken from the parent formation to which it is attached by conventional practice through the use of a conventional core catcher 56 which is secured to the bit head I.

It will be observed from the foregoing that the washing out of the inner core barrel 8 is permitted by virtue of the fact that the valve 33 is initially placed in its open position and l latched in that position by the engagement of the pawl 38 with the latch 31, and that the sealing oi of the fluid communication between the channel through which the drilling iiuid is circulated and the interior of the inner core barrel I is effected by the closing of the .valve 33.

Attention is also called to the fact that the closing of this valve is automatically initiated by the beginning of the circulationof the drilling iluid which is employed to wash the interior of the inner core barrel. This operation is permitted by the use of the timing mechanism 32, the construction of which is illustrated in detail in Fig.

The timing mechanism 32 comprises a cylinder 51 within which is reciprocably mounted a piston 58, the piston 58 being secured to the aforementioned valve stem 36 and adapted to make a sealing fit with the walls of the cylinder 51 as by means of piston rings or suitable packing material 59. The cylinder 51 is fitted with upper and lower cylinder heads 60 and 6I, fluid leakage around the valve stem 35 being prevented by means of suitable packing glands 62 and 53. The entire space within the cylinder 51 not occupied by the piston 58 is filled with a suitable iluid, dashpot oil being found eminently satisfactory for this purpose.

The piston 58 is` provided with one or more bores 54 which extend between the upper and lower surfaces of the piston 58- to permit passage of uid therethrough as the piston is moved in the cylinder. Each of these bores 64 is provided with a check valve 65 which operates to permit only downward flow of iluid through the bores 64.

This permits the piston to be readily moved to f the upper end of the cylinder 58 at the time the valve spring 34 is compressed to latch the valve in its open position. One or more timing openings 66 are also extended longitudinally through the piston 53' so as to provide for upward flow of iluid as the piston 58 moves downwardly in the cylinder 51.

It will be readily appreciated that the combined travel of the piston 58 in response to the downward force exerted thereon by the spring 34 after the pawl 38 has been released from the latch 31. It will thus -be seen that when the pawl 35 is released as by the starting of the slush pumps at the ground surface, the valve 33 immediately begins a slow downward movement in response to urging of the spring 34 and that the rate of this downward movement is so controlled as t0 permit sutiicient length of time to elapse between the starting of the slush pumps and the closing of the valve 33 to provide for the complete cleaning of the inner core barrel 8.

Reference has been made hereinbefore to the desirability of obtaining a registration of the inclination of the well bore to the vertical at the point the core is taken. Our invention comprehends the use of the valve 33 and the timing mechanism 32 associated therewith as a means for obtaining such a registration. As shown in Fig. 5 the valve seat member 26 is preferably provided at a point below the valve seat 35 with a spider B1 which isused to support a pendulum 88. The pendulum 68. preferably comprisesan upwardly extending rod 69, the upper end of which is sharpened to a point as indicated at 10 and the lower end of which carries a weight or plumb-bob 1I. 'I'he rod B9 is supported by the spider 61 by means of a universal joint 12 permitting free pivotal movement of the rod 63 about the joint 12 iti any vertical plane so that the rod 63 will remain in a truly vertical position irrespective of the inclination of the axis oi the housing 25 within -which'it is supported.

The lower face of the valve 33 is preferably recessed as indicated in Fig. 5 to frictionally retain an indicator disk 13 and the length of the rod 89 is so adjusted that the point 10 will provide a pin prick or depression in the card 13 when the valve 33 is moved to its completely closed position. This relationship is illustrated herein in Fig. 6. The indicator card 13 may, if desired, be provided with a series of concentric circular graduations eachl representative of a predetermined angular amount of `inclination of 'the well bore so that when the core cut by the' by recessing the valve 33 behind the card 13 and by filling this recess with a resilient or semiplastic material.

Attention is called to the fact that the registering of the angle of inclination of the well bore to the vertical is initiated after the device is lowered into the well bore by the starting of the slush pumps at the ground surface. It will be readily appreciated that the position occupied by the pendulum relative to the housing 25 will be seriously disturbed by the flow of circulating fluid past the weight 1I so that it is advisable to stop the slush pumps when they have been operated a sufficient length of time to completely wash the inner core barrel 8 but before a suflicient time has elapsed to permit the timing mechanism 32 to cause the card 13 to be moved into engagement with the plumb-bob point 10, thus providing a period o'f time during which the plumb-bob is permitted to come to rest and assume a truly vertical position.

'mechanism in operation, that other forms of timing devices and other asiasvc After a sucient length of core has been cut and the core has been'broken from the parent formation in the manner hereinbefore described,

' the drill string is removed from the well bore to core 52 from the core barrel t or, if preferred, the n adaptor 2 may be unscrewed from the working barrel 3 at the threaded connection lib so as to permit the withdrawal from the working barrel 3 of the sleeve IB andthe inner core barrel I carried thereby. The caps i3 and I9 may then be removed from the sleeve l and the core barrel' 8, respectively, to permit extraction of the core 52 through the upper end of thecore barrel I.

Access may then be had to the indicator card 13 by separating the housing 25 from the valve seat member 26 atthe threaded connection 2d.

From the foregoing it will .be observed that Wel have provided a core drilling device including a core receiving barrel which is so constructed as to permit the replacement of chip laden drilling fluid through the interior o said core barrel; f i

spring means normally urging said valve toward a closing position; releasable restraining for holding said valve in an open position; means iiuid in the barrel with clean drilling uid prior to the time the drill is operated to-take a core,

It will be further observed that the device of our invention 4permits the washing of the core barrel to be terminated aftera predetermined length oi time to thereafter prevent the drilling fluid from being forced into the core barrel.

Attention is called to the fact that the device of our invention includes a means which ls responsive to an operation performed at the ground surface (in the modication shown herein the operation of starting the slush pumps) lfor changing the path of ilovv of the drilling iuid from one extending through the core receiving barrel to another exteriorly thereof and that such change in path of flow occurs a predeter.

mined time after the perfomance of the operation at the ground surface. g

` While we have shown and described a buttery coacting with a hydraulically timed value 'lor responsive to liow of duid in said drill string for releasing said restraining means; and means Olpi erable independentlyof iiov.' of uid in said drill string for delaying the actual closing of said valve for a predetermined time after release of said restraining means. i

2. In a core drillingdevice including a tubular working barrel having means for attachment to a vstring oi.' drill pipe and carrylng'a coring bit. the combination of: a tubular core receivingv barrel carried by said working barrel and having an opening in its upper end through which drill-- ing fluid may be circulated; valve meansactuatable to close said opening; means controllable from the ground surface to actu'ate said valveV means; means on said core barrel for determining the angle of inclination of said barrel to the vertical; and means responsive to actuation. of said valve means-for producing a registration ci said angle. A i

3. In a core drilling device including a tubu lar working barrel having means for attachment to a string of drill pipe and carrying a corlng bit.-

the combination ot: a tubular core recei bara rel carried by said working barrel and having an opening in its upper end throughv which drilling iiuid may be circulated; `valve means actuatable to close' said opening; means responsive to new oi iiuid in said drill string for actuating said valve means; means on said core barrel for de= termining the angle of inclination of said barrel to the vertical; and means responsive yiao-"actua-1 tion of said valvemeans for producing a regisl tration of said angle.

performing this operation, it will be understood that this invention is not hydraulic device for eil'ectlng the desired timing function, nor is this vinvention limited to the employment of a buttery for placing the timing types of ow responsive means may be used with equal satisfaction for starting and performing the timing operation. y 4

. While we have shown and described the preferred embodiment of our-inventicn, we do not desire to be limited to any of the details of construction shown or described herein,V except as defined in the appended claims.v

We claim:

l. In a core drilling device including a tubular working barrel having means for attachment to a string of drill pipe and carrying a coring bit, the combination of: a tubular core receiving barrel so disposed within said working barrel as to dene an annular luid passage between said barrels, said core barrel having an opening near its upper end establishinga fluid interconnectionstring will be simultaneously passed through said passage and said core barrel; valve means for closing said opening to prevent passagerot 75 i limited to the use of a' it being understood' 4. In a core drilling device including a tubular workingbarrel having means for attachment to a string of drill pipe andvcarr'yihg a caring bit, the combination of: a tubular core receiving barrel carried by said working barrel and having an opening in its upper end through which drill' ing nuid may be circulated: valve means mounted for movement to a position closing said opening; means. responsive to iiovv of uid in said drill string for moving said valve to said cl position; inclinometer'means on said core barrel for determining .the angle of inclination of said barrel to the verticaiyand registering means carried by said valve in a position toengage'said inclinometer means upon movement of said valve s. in s core drilling device including s meuf f lar working barrel having means for attachment drilling uid may be circulated; 'valve means' mounted for movement to a position closing said opening; means controllable, from the ground-' surface to move said'valve meansto said closed position; a record chart carried by said valve.. means; a pendulum carried by said com barrel for determining the angle orinclination of said barrel from the vertical, said pendulum including y a pointer for indicating said angle: anduieansI to a string o: drm pipe and carrying s caring on, .f

the combinationoi': a tubular core receiving barrel carried by said working `barrel and having an opening in its upper end throughxwhich mounting said pendulum in such position. as to engage said pointer with said chart when said valve is moved to said closed position to thereby record the angle determined by said pendulum,

6. In a core drilling device'including atubur lar working barrel having means for attachment to a string of drill pipe and carrying a coring bit, the combination of: a tubular core receiving barrel so disposed within said working barrel as to define an annular fluid passage between said barrels, said core barrel having an opening near its upper end establishinga uid interconnection between the interior of said core barrel and said passage, whereby duid supplied through said drilll string will be simultaneously passed through said passage and said core barrel; valve seat means surrounding said opening; valve means including a valve stem guided for axial sliding movement oi' said valve into engagement i RALPH A. PHILLIPS. MORTIMER L. CLOPTON.

Images