US1724913A - Shock-absorbing apparatus for drilling machines using wire cables - Google Patents

Description

Aug. 2o, 1929.

SHOCK ABSORBING APPARATUS FOR DRILLING MACHINES USING WIRE CABLES F. F. DAvls v 1,724,913

Aug. 20, 1929. F. F, DAvls 1,724,913

SHOCK ABSORBING APPARATUS FOR DRILLING MACHINES USING WIRE CABLES Filed May 6, 1926 2 Shets-Sheet 2 111; 4 116 g 5 ai: l f 2gb l" 5 /0 Fig. v 4K 'l 4Z lNvENToR FranciSFa/colzerawl ATTORNEY 'l Mig@ Patented Aug. 20, 1929.

UNITED STATES PATENT OFFICE.

FRANCIS FALCONER DAVIS, OF MONTEREY, CALIFORNIA, ASSIGNOR TO FRANCIS HARLEY DAVIS, OF MONTEREY, CALIFORNIA.

SHOCK-ABSORBING APPARATUS FOR DRILLING MACHINES USING WIRE CABLES.

App1icatio. filed May 6, 1926.

The present invention is an improvement of the devices disclosed in my co-pending applications, eSrial Nos. 756,936 and 80,956 and relates broadly to cable drilling machinery, but refers more particularly to portable drilling rigs used for vspudding-in shallow water wells, quarry blast holes, and the like; such rigs as customarily have a derrick or mast provided with a crown sheave at or near the top thereof for the support and service of the tool-carrying sable.

Specifically my device may be classed as what, in driller parlance is known as, a cracker several forms of which are known to the prior art, but in relation to which my present device is a novelty and a decided improvement.

A cracker device is for use when drilling with the nonelastic steel wire cable instead of the elastic fiber cable so largely in present use. A cracker' consists of a liber cordage member interposed at some point between the drilling tool and the spudding beam so as to deaden the shock that attends drilling when steel wire cable is used as the tool carrier.

One, and probably the most successful form of cracker in present use in the art consistsv of a length of manila cable or hawser, about one hundred feet long, whose lower end is attached to the rope-socket of the drilling tools and the upper end thereof is attached to the lower end of the wire cable.

lith a cracker of this length (which however is obviously inadmissible in shallow holes) a satisfactory simulation of a. cordage-carried drill can be secured even though the remainder of the cable leading from the top of the cracker to the winding drum be non-elastic.

There are also various forms of derrick mounted crackers which operate with more or less measure of success. By the use of the present cracker a perfect simulation of the drilling action of an elastic cordagecarried drill can be attained while wire-line drilling, with the added advantage of being able to drill with a rapid drilling motion irrespective of the depth of the hole, of the weight of the drill employed, or as to whether or not the drilling is being done in a wet hole or a dry one.

The increasing demand for shallow drillings makes the use `of wirecable in lieu of Serial No. 107,197.

the liber cable so largely in present use a matter of serious importance, wire being less expensive than ber cordage, longer-lived under the severe stresses which accompany drilling by the s pudding process.

An object of this invention is to provide a drilling-machine derrick, or mast structure, with an improved method of housing a movable crown-sheave bearing.

A further object is to provide an elastic member, or cracker, for the support of the crown-sheave bearing, said elastic cracker being adapted to receive tensional adjustments from above.

Another' object is to provide a drill-supporting structure with a lifting means adapted to apply strain to a cracker member in an upward direction.

An additional object is to provide a girthlike cracker adapted to be tensed by upward strain applied at a point of the derrick structure that is higher than the level of the bight of the said girth.

Another object is to provide a winding means adjacent the top of a derrick structure, the said means being adapted for applying regulative up and down adjustment to an elastic girth-likeelement.

Another object is to provide a rigid spacing means adapted' to ride on the bight of the elastic cracker element for the support of a crown-sheave bearing in a buoyantvmanner as regards the longitudinal axis of the said derrick structure.

A further object is to provide asan article of manufacture, a crown-sheave block adapted to it the top of a derrick structure; within the said block a piston-like crownsheave bearing adapted for limited up and down movement, said block embodying a winding means adapted to apply strain to an elastic cracker member.

Another `object is to provide a crownblock structure with a taperedY socket adapted to fit a mast or derrick top and to slip downwardly over the said top so as to compensate for shrinkage.

A further: object is to provide a structure of great eiciency and one that is not liable to get out of order.

Another object is to provide an anuXiliary cushioning means to aid the elastic element aforesaid at the end of the down stroke;

Other objects and advantages will appear during the course of the following description.

. In the accompanying drawings forming a part of this specification, and in which like numerals are employed` to designate like parts throughout the same,-

Figure 1 shows a side elevational view ot a drilling machine mast equipped with my apparatus.

Figure 2 is a rear elevation al view of the apparatus.

Figure 3 is a cross-section taken on the line ll-vll of Figure 2.

Figure il is a genera-l side View of a drilling machine embodying my apparatus.

Referring now in close detail to the drawings: Figure l shows the non-elastic drilling cable 6 leading from the hoisting drum 7 round the contacting circumferential portions of the sheave, thence passing under the sheaves fL and S and over the crownsheave 9 and on to the rope-socket 115 at the head of the drilling tool.

As best shown in Figure 2, it will be seen f that the crown-sheave 9 is carried by the shaft 11b in the crown-sheave bearing 11, the said shea-ve 9 being adapted for revoluble movement either with the shaft 11b or as a loose member on the said shaft, there being a transverse perforation 11e suitably7 disposed in the wall of the crown-block structure 10 Jfor the purpose of inserting said shaft in said bearing for the revoluble support of the said crown-sheave.

The bearing 11 is adapted to slide up and down for a predetermined distance within the internal space 11a of the crown-block structure 10, the said bearing being provided with the suitablycored recess 43 and with the downwardly-projeciing shank 12, the said snank being adapted for 'fastening ot the bearing 11 to the rigid spacing-means 17, which means may well be either a shaft of suitable sir/.e and shape or a pipe. The shank 12 as shown in Figure 2 carries the cushion-spring 13 which is retained in place bythe keeper lila, an annular ring, the said keeper being prevented from falling oil the shank 12 by the keeper-pin 1l. The bearing 11 is inserted from the top of the struc-A ture 10 by irst removing the cover 36.

As shown, the pin 14- serves to secure the spacing means 17 to the shank 12, the said shank being bored out to receive the upper end ,ot the said means 17.

A suitable distance belowT the end of shank 12 is the abutment 15 preferably formed integral with the body of the crown-block. structure 10, said abutment being provided with a vertical perforation or abutment-hole 16, said hole being of sufficiently large diameter 'for the shank 12 with the slightly-projecting keeper-pin 14 to play in and out of, although suiliciently restricted in diameter to form an abutment for the keeper 14a to abut against when t-he drill is being lifted.

The interior portion of structure 10 from the under side of the abutment 15 down to the lower end 22a is conformed to lit over the head of the mast 23 which is tapered on all four sides and lett a trifle large to allow for shrinkage of the timber, consequently there is a space as 22b left between the under side of the abutment 15 which is designated 22 and the upper end of the mast 23. New, as thesaid space would gradually diminish in height due to the downward travel ot the structure 10 on the taper et the mast 23, when effected by the shrinkage of the said nast, the recess 38 is provided in the top o1" the said mast for the accommodation of the shank 12.

The mast 23, as best shown in Figure 1, is of composite structure, the lower portion thereof being composed or" the channels 24-2-1 which extend upwardly 'for a considerable distance from the ground, the said channels being secured by bolts as 112 to the lower portion of a timber of suitable length to give the required height to; the derrick structure, and, for the purpose of illus ation, say twelve inchesrby twelve inches in cross-section; a suitable taper being given to the upper end thereoi1 as' described so that the ycrown-block structure 10 which is preterably a steel casting may be slipped over the top ,of the said mast and wedge itself thereon without need of other attachment, as all the tendency of the drilling operations is to drive the structure farther and more firmly over the mast head. lt is obvious, however, that such a crown-block structure 10 could be adapted for use on derricks of different construction from that above mentioned, it could be used with a derric.; composed entirely of structural steel elements, or one made of pipe, without deparing from the spirit of the invention.

The spacing means 17 passes down through the abutment-hole 1G and down through the central axis of the member 23, (which is bored to receive it) until the lower end of the said means projects a suitable llO distance below the lower end of the mem- Y ber 23 at the point 39 for the attachment of the pressure-toot 18 to the said lower end orP means 17, which attachment may be obtained by the insertion of the end of means 17 into a socket as 2O and secured therein by suitable means, removable or not.

The pressure-foot 18, as best shown in Figure 2 is located between the two channels 2l-24= and stands upon the bight of the elastic girth-like member 19 the parts of which 19a and 191 are seen'to extend upwardly one one each side or the mast structure 23. The said parts being adapted to be pulled evenly in an upwarddirection by winding means pawls 32-32, the said ratchets in the to which the said parts may either be attached direct or be attached by means of the rope socket 27 27 and wire rope extension as 28-28, or by other suitable means.

As best shown in Figure 2, the parts 19a and 19h of the elastic girth-like member 19 are pieced out by the flexible wire rope 28-28 the ends of which are secured to the drum 29-29 the said drums being secured to the shaft 30 which is rotatable in the bearings 3LP-34 and adapted to exert upward strain upon the member 19 when leverage is applied to the handle 31 in a counter clock-wise direction, and a consequent flexing of the said member with a clock-wise movement of the said handle 31, both movements being under the regulative control of the ratchets 323-33 in co-action with the present instance being' formed integral with the drum 29-29, the said pawls being secured appropriately to the flanges 352t and 35h.

The operation of my device is as follows Assuming that the string of drilling tools is suspended over the crown-sheave 9 by the non-elastic tool carrying wire cable 6 whose slack has been taken up on the hoistingdrum 7 and held in check by brake means not shown as it forms no part of the present invention. In this position the lower surface of the annular keeper 14a rests in contact with the upper surface of the abutment 15 so that such weight as is present is borne by the cushion-spring 13.

Assuming now that counter clock-wise movement has been imparted to the handle 31, and that the drums 29-29 have been rotated so as to take up the slack and apply a lifting influence to the extension ropes 28-2S, thereby causing a direct upward pull upon the elastic girth-like member 19; assuming further that an upward pull of sufficient degree has been applied to the said member so as to elevate the crown-sheave 9 until it reaches a. level approximately half way up the mouth 37 of the crown-block structure 10,-as best shown in Figure 2,- and, that regulated adjustment of the parts involved is maintained by the co-action of the pawls 32-32 with the ratchets 33-33 until the drilling tools are lifted clear off the bottom of the drill-hole and are carried on the said girth-like member 19 in a buoyant manner, similar to that of a child seated in that well known device called A babybouncer.

Vhen the drill is in action, as each downward stroke of the bearing 11 nears its downward limit, just when the strain on the girthlike element 19 is becoming the most severe and tends to fatigue the fibers of the said girth 19, the cushion-spring 13 comes into play in conjunction with the abutment 15 and relieves the excessive strain that otherwise would have to be borne by the member 19 alone.

To perform the kdrilling act a suitable agent transmits power from the drum-shaft 2 to the spudding beam 3 through the crank 4 and pitman 5 thereby causing the beam 3 to oscillate in an up and down manner; thus, by alternately depressing and releasing the non-elastic sable 6 the drill is caused to reciprocate. Said cable 6 being nicely fed out from the hoisting drum 7 as the hole deepens; the weight of the drill meanwhile being borne in a shockless manner on the elastic girth-like member 19 in co-operation with the cushion-spring member 13 as explained.

It is to be understood that the form of my invention, herewith shown and described is to be taken as a preferred example of the same, and that various changes in the shape size and arrangement of parts may be resorted to without departing from the spirit of the invention, or the scope of the subjoined claims.

I claim 1. In an apparatus of the kind described, an elastic girth-like element depending fromv a mast or derrick structure, a crown-sheave adapted for rotary and up and down movement, the crown-sheave supported on the said element. by a spacing means, and regulative means for tensing or flexingv the said element from above, substantially as described and for the purposes set forth.

2. A shock-absorbing apparatus adapted for use as a crown block for a drilling-machine using Wire drilling cable, said apparatus comprising in combination, a structure adapted ixedly to surmount a derrick-like supporting body, said block being provided with a revoluble sheave mounted in a bearing adapted for up and down movement, elongated slots in said block being disposed at right angles to the axis of said sheave and of sufficient lengt-h and apt location to accommodate the up and down play of said sheave, an elastic element on the. structure, spacing means eo-acting with said bearing and with the elastic element for the resilient support of said sheave, together with regulatively-adjustable means carried, by said block for tensing or relaxing said elastic element so as to adjust the height of said sheave relative to the said slots when carrying tools of different weights.

3. In a shock-absorbing crown block for a drilling machine having means for attachment to a derrick structure, a revoluble crown sheave mounted in a bearing adapted for up and down movement within said block, an elastic girth-like element depending from said block, a spacing means engaging said girth for the resilient support of said bearing, regulative means for tensing and flexing said element from above and a spring means independently carried by said fil bearing and adapted to Contact at the ends of each down-stroke of said bearing with an abutment, said Contact thereby compressing said spring and providing cushioned relief for said element when under severeSt strain.

4. In an apparatus as specified in claim 1, said Crown sheave being suitably mounted in an elongated, tapering, shell-likevstructure adapted to lit on to the free upper end of a 10 mast or derrick.

5. In an apparatus as set forth in claim 1,

and in combination; said sheave suitably,

mounted in an elongated, tape-ring structure, the lower end of said structure making tapering connection with the top of a mast or derriek, and said regula/tive means carried by the structure.

In testimony that I claim the above as my own I have hereunto subscribed my name this 24th day of April, 1926.

e FRANCIS FALCONER DAVIS.

CERTIFICATE OF CORRECTION.

Patent No. 1,724,913. Granted August 20, 1929, to

FRANCIS FALCONER DAVIS.

It is Iiereby certified that errer appears in the printed specification of the above nmnlsered patent requiring cerrectienas follows: Page l, line 2, for "copending" read copending"; line 3, for the misspelled word "eSrial"-read "Serial"; line 11, for "sable" read "cable"; line 106, for the misspelled word "anuxiliary" read "anxiliary"; page 3, lines 9 and 21, for drum" read "drun1s"; and line 74, for "sable" read "cable"; and that the said Letters Patent should be read With these eorrectiens therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 15th day of October, A. D. 1929.

t: M. J. Moore,

(Seal) Acting Commissioner of Patents.

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