US1530803A - Rotary drill - Google Patents

Description

March 24, 1925. 1,530,803

w. A. ANDERSON ROTARY DRILL File'd Nov. 2'7, 1922 3 Shets-Sheet 1 INVENTOR. Mil/AM .4. 4.4/oenscw BY I ATTQRNEYS.

March 24, 1925;

. 1,530,803 w, A. ANDERSON- ROTARY DRILL Fild '3 snets -shet 2 W. A. ANDERSON ,fnmw MM. 4 it/I16 4! March 24, 1925.

I I I I I l I I l I I l I I l l l l L I l l l I l IT Patented Mar. 24, 1 925 I A HUNIIT-ED STATES WILLIAM ALEXANDER ROTARY DRILL.

To allaolzom it may concern:

Be it known'that I, WILLIAM ALEXANDER .ANDEnsoN, a citizen of the United States,

resident of San Francisco, county of San Francisco, State of California, have invented a new and useful Rotary .Drill, of which the following is a specification.

The present invention relates to improve-- lessen the labor of such boring work, and to reduce the cost of the apparatus. It is a well known fact that in the present practice of hydraulic rotary drilling the shaft carrying the bit extends from the bottom of the well to the surface of the ground and a certain distance above the ground so that it maybe driven from a power plant which is supported independently of the shaft. In my device the power plant is brought into one unit with the shaft and moves down-.

wardly with the same as the hole grows deeper so that it is unnecessary to extend the shaft, a flexible connection being maintained between the shaft and the power plant carrying unit and the surface ofthe ground whereby the unit may be pulled upward when it is desired to change the bit or when the intended depth 'has been reached. A further advantage of my device is that it becomes exceedingly easy to change the bits, and to take core samples of geological formations that the drill is passing through. In present day practice it happens quite frequently that the bit grows dull very quickly and its takes considerable time to change the bit, increasing as the depth grows greater. My device comprises a single unit connected to a hoisting apparatus above the ground by means of a cable and a hose and its takes very little effort on the part of the men as well as very little time to lift the unit out of the well and replace the bits or to take core samples of earth formation penetrated. A further object of my invention is to provide means whereby the dbris may be removed from the bottom of the well with very little difliculty,.my,

Application filed November 27, 1922. Serial No. 603,641.

(PATENT. .oFFI-cE;

AnnE'Iis'oN, or SAN mancisoo, oauronm. I

means being adapted for the flooding of the" dbris as well as for the removal of the same by' air suction or pressure. The latter method isof particular importance where water israre and where it is desired to make a close. study of the different strata passed by the drill.

With these and other objects in view I have illustrated the preferred form of my invention in the accompanying drawings, in which Figures 1, 2, 3, 4. and 5 represent a vertical section through my device, Figure 1 showing the top portion, Figures 2, 3 and 4 the central portion and Figure 5 the. bottom portion, Figure 6 a horizontal section taken along line VI-VI of Figure 2, Figure 7 a bottom plan view, Figure 8 a vertical section along line VII-VII of Figure 2, and Figure 9 a sectional detail view of an expansion chamber controlling the amount of oil contained in the device. While I have shown only the preferred form of my invention, it should be understood that various changes or modifications might be made,

within the scope of the claims hereto attached without departing from the spirit of the invention.

The housing (1) of my device comprisesa tube (2), an upper casting (3), closing the top of the tube and secured in its place by means of screws (4) and a lower casting (6) closing the bottom of the tube and secured in its place by means of screws (7). I prefer to drive my drill by means of an electric motor and therefor have confined my illustrations to; that particular drive although it will be readily understood that, other means for driving my drill may be used such as compressedair. A particular feature of my invention is that I use two concentric shafts each, of which carries'a bit of its own and both of which are rotated simultaneously but in opposite directions at-the same or different speeds. These two shafts are run by the same motor or motors, one of them being connected with the armature of the motor while the other is drivenby the field, both of which are rotatably mounted in the housing. Referring to the drawings it will be seen that the inner shaft (8) which is coupled in several places as at (8') and (8") extends from the upper casting downwardly through the bottom casting and carries below said bottom casting the bit (9 while the outer shaft (11), coupled-as s own at I (11) and (11") surrounds the inner shaft concentrically so as to leave sufiicient space between the same for the different windings and other devices hereinafter to be described and narrows at the bottom as shown at (12) so as to make a running fit on the inner shaft when it passes through the lower casting. The outer shaft also carries at the bottom a bit (13) disposed concentrically relative to the bit (9). The inner shaft is held in proper alinement by its engagement with t e upper and lower castingsaswell as by suitable guldes (14) provided with anti-friction bearings (16).- The outer shaft is maintained in its position by means of suitable guides 17) and anti-friction bearings (18) reducing the friction to a minimum. A suitable thrust bearing (19) is provided below the body portion of the outer shaft to support the rotating field and armature, and another thrust bearing (21) above a collar (22) to bear against a guide (20) for holding the shaft against upward motion. It will be seen that suitable stufling boxes (24) are provided in the top and bottom castings to prevent any leakages around the shaft.

For driving the drill I preferably use one or more single-phase or polyphase induction motors, the armatures (26) being .associated with the inner shaft while the fields (27) form a part ofthe outer shaft. Suitable wire connections may be made by brushes (28) engaging collecting rings -(30). It will be readily understood that if neither the armature nor the field are held stationary, both of them will under normal conditions develop an equal tendency to rotate whenever electric current is supplied. The rotation of the armature will be in the'opposite direction to that of the field so that when the motor is working the two bits (9) and (13) are rotated in opposite directions. It will be seen from Figure 5 that the bell shaped bit (13) surrounds the bit (9) and is set to out in the opposite direction. Looking at the device from below the inner bit cutson a rotation in aclock-wise direction while the outer bell-shaped bit cuts on a counterclockwise rotation.

The inner shaft is hollow and extends, slightly reduced, throughthe upper casting, the upper portion being'threaded as at (33) to receive the end of a hose not shown in the drawing. At the lower end of the inner shaft the bore extends through the upper portion of the bit (9) and finds two outlets (34) through the slanting sides (36) of the inner bit.

It has been noticed that under normal conditions the inner and outer shafts have an equal tendency to turn in opposite directions. But it will be understood that if one of the two bits carried on said two shafts should meet with an obstacle such as a hard rock formation which would not affect the other bit this fact would have a natural tendency to slow down the bit meeting with the obstacle and might even cause the latter bit to become stationary, while the other bit would race correspondingly faster without doing any work. To overcome this I provide the device shown in Figure 6, by means of which the two shafts are connected to each other in such a manner that they have to maintain the same speed ratios. ThlS devlce comprises an internal gear (37) associated with the which latter is held against rotation by means referred to hereinafter.

As long as both shafts have a tendency to run at the same speed ratios, the pinions (39) idle between the two gears (37) and (38). But as soon as one of the shafts develops a tendency, due to a lighter load, torotate faster than the other one the pinions (39) become active and transmit any excess power from the shaft running under a lighter load to the other thereby assisting the latter and overcoming the obstacle referred to. In this manner both shafts are always forced to rotate at the same speed ratios and all the'power transmitted'to the shafts will be utilized.

To prevent thehousing itself from rotating within the hole drilled I provide the device shown in Figure 1 comprising a yoke (42) secured to the top casting (3) by means of screws (43) in the yoke (42) are pivotally supported a plurality of links (46), the outer ends of the links on either side of the yoke being joined by bars (47). The top ends of the bars are connected to a central head (48) by pivoted arms (49) and the head is provided with an eye (51) adapted to receive a cable or wire rope con-- nection not shown in the drawing, whereby the whole device may be lifted. As long as the device is supported by the attachment, which connects with a cable, the

bars (47) are drawn inwardly to the yoke,

which tendency, however, is opposed by the spring(52) surrounding the stem (53) extending downwardly from the head (48) through the top member of the yoke. The spring bears against the underside of the top member of the yoke and a nut (54) threadedly engaging the stem so that the tension of the spring may be adjusted. When the bits strike the bottom of the hole and the weight of the device is wholly or partially taken off the cable and the head (48), the spring (52) forces the bars (47') away from the yoke into contact with the wall of the hole whereby the whole device is prevented from rotating.

As a particular feature of mydevice, should be mentioned my oil system. To prevent the device from collapsing due to external pressures or to internal pressures as well as to prevent leakages it is desirable that the space between the housing and the shafts be kept filled with oil or other fluid continuously. But since the oil may heatduringthe operation of the device it is at the same time necessary to provide means for allowing of expansion of the oil or fluid. For this purposeI provide the expansion chamber (56) shown in detail in Figure 9 which consists of a tubular cup (57)- terminating at the bottom in a threaded nipple (58). adaptedto be screwed into the top casting(3) and communicating with a passage (59) extending through the casting. A cap (61) slidably engages the cup and is normally pulled downwardly by aspring (62). )Vhen the oil or fluid, which may be forced into the housing through any suitable hole as at (63) in the lower end of the housing (see Figure 4) expands, it forces the cap upward until the latter clears a. perforation (64) in the cup which allows any excess oil or fluid to run through the perforation (64). In this manner the housing is kept filled with'oil or fluid continuously without exposure to injury by internal pressure caused by the expansion of the oil or fluid due to heat. Suitable means are pro vided which may consist of. adjustable spring or weight tension on the cap (61) which will maintain the oil or fluid pressure against external pressures. This difference being under control by the above mentioned tension.

The operation of the device will be readily understood from the foregoing descrip tion. The whole device is suspended from a suitable derrick and the hose leading to the bore in the inner shaft as well as the electric connections are wound on suitable drums so that all three, the lifting cable, the hose and the electrical connections, can follow the drill as the latter recedes from the surface. After the device has thus been properly placed and begun to work hardly any further change is necessary sinceino shafts need to be coupled and the device is limited in its penetration only by the length of the cable holding it. .If it becomes necessary to change the hits the whole device may be hoisted upward with very little loss'of time. To remove the dbris I either use hydraulic or pneumatic apparatus. The use of water does not involve any new features and it may be 'ust briefly stated that the water is admitte through the hose referred to, to the inside of the inner shaft pres bits thereonfformed to attack the bottom of a well in opposite directions, electro-magnetic means causing relative rotary motion of'the two shafts and compensating means causing both shafts torotate in predetermined relation irrespective of the load encountered byeither shaft.

2. In a rotary drill of the character described, two conc'entric'shafts having drill bits thereon formed to attack the bottom of a well in opposite directions, electromagnetlc means causing relativerotary motion of the two shafts andmeans associated with the two shafts for maintaining their respective speed ratio whereby power is transferred from oneto the other incase the latter is subjected to a heavier load.

In a rotary drill, an electric motor having a revolving field and a revolving armature, drill bits attached to the field and the armature, a stationary casing surrounding the. motor, and compensating means for the field and armature anchored to the casing for causing the field and armature to revolve at a predetermined speed ratio irrespective of load variations.

4. In a rotary drill, an electric motor having a revolving field and a revolving armature, drill bits attached to the field and the armature, a stationary casing surrounding the motor, a ring within the easing anchored to the same having pins extending from its face and pinions secured to said pins and an internal gear associated with the field and an external gear asso ciated with the armature engaging said pinions for maintaining a predetermined speed ratio of the field and the armature.

5. In a rotary drill of the character described, a housing, a shaft and a motor actuating the same supported therein with freedom of rotary motion, and means associated with the housing for automatically maintaining" and regulating internal 'presadjustable Ii sure of a fluid against external pressure, vsaid means comprising an expansion chamber communicating with the housing, a cap slidably engaging the same, adjustab e ing means for seating the cap and an outlet normally covered by the cap adapted to be cleared when'the internal pressure exceeds a redetermined de ee. In a rotary rill, an electric motor having a revolving field and a revolvm armature, drill bits attached to the fiel and'the armature, a casing surrounding the motor, compensating means for the field and armature anchored to the casing for causing the field and armature to revolve at a predetermined speed ratio irrespective of load conditions and means for holding yieldthe casing 11 ainst rotation made to yield when upwar ull is exerted thereon.

8. In a sing e unit rotary drill comprising a casing, 21 bit carrying shaft rotatable therein and a ower lant r actuating the shaft mounte in t e casing, means for holding the casing against rotation comprising a plurality of links pivoted to opposite sides of the casing, bars connecting the extreme ends of the lmks on either side,

a central head, pivoted links connecting the

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