US2372232A - Spooling device for cable tool drills - Google Patents

Description

March 27, 1945. H. w. THORNBURG 2,372,232

SPOOLING DEVICE FOR CABLE TOOL DRILLS Filed Aug. 13-, 1942 2 ,sheets sheet 1i I -Maw ATTORNEYS,

H. W. THORNBURG SPOOLING DEVICE FOR CABLE TOOL DRILLS March 27, 1945.

Filed Aug. 13, 1942 2 Sheets-Sheet 2 V INVE BY 2am I'/ ATTORNEY 5 coils to become crossed over other coils.

Patented Mar. 27, 1945 SPOOLING DEVICE FOR CABLE TOOL DRILLS Herbert W. Thornburg, South Milwaukee, Wis.,

assignor to Bucyrus-Erie Company, South Milwaukee, Wis., a corporation of Delaware Application August 13, 1942, Serial No. 454,641

11 Claims.

My invention relates to new and useful im-- provements in spooling devices for cable-tool dril1s.

Such drills, per se, are well known.

In such drills a rope passes, from a winch drum on the main frame, around a heel sheave at or near the pivot of a spudding beam, thence under a sheave at oscillating end of the spudding beam, thence over a sheave at the upper end of a mast, and thence vertically downward into the hole useful details, which will be readily evident as the description progresses.

My invention consists in the novel parts and in t the combination and arrangement thereof, which which is being drilled in the ground. At the lower end of this rope is a string of percussion drillingtools. The spudding beam is oscillated by a pitman, actuated by a rotating crank. As the rope is payed out to lower the tools as the hole grows deeper, or is taken in to withdraw the tools for any reason, it is desirable that the reach of rope from the winch-drum to the heel sheave shall move from side to side, always in a plane perpendicular to the axis of the drum,

spooling the lays of the rope evenly off of or onto the drum; and that the heel sheave shall move from side to side and change its orientation, so as always to lie substantially in the plane defined by the two reaches of rope which run from this sheave.

v Accordingly it is the principal object of my invention to devise a mounting for the heel sheave, such that the heel sheave will automatically thus move and thus orient itself, under the influence merely of the tension in these two reaches of rope.

During spudding, there is a tendency to throw slack into the rope at the end of each upstroke of the tools. Furthermore, on the downstroke the rope is stretched and has a tendency to untwist; and, when the rope becomes slack a the end of the upstroke, the rope tends to it st up again.

The net result of these tenden ies is for the coils of rope on the drum to expand, and for some This damages the rope. I

So it is necessary for a spooling device, in addition to properly shifting and orienting the heel sheave, also to clamp the rope just ,sufiiciently tightly to prevent this whippin and twisting, and yet permit the gradual slipping of the rope past the heel sheave as the tool dig the hole deeper and deeper. Such a clamping means should also be readily releasable during hauling up or lower ing of the tools.

Accordingly it is a further object of my invention to incorporate into my spooling device such a clamp.

In addition to my principal objects, above stated, I have worked out a number of novel and are defined in the appended claims, and of which one embodiment is exemplified in the accompanying drawings, which are hereinafter particularly described and explained.

Throughout the description, the same reference number is applied to the same member or to similar members.

Figure '1 is a plan view of a drill embodying my invention.

Figure 2 is a side elevation of the same drill.

In these two figures, the associated parts of the drill have been shown very schematically, and much of the drill (well known to the art) has been omitted.

Figure 3 is a slightly enlarged elevation of one of the links of my invention, taken along the lines 3-3 of Figure 1.

Figure 4 is a slightly enlarged elevation of the heel sheave of my invention, taken along the lines 4-4 of Figure 1.

Figure 5 is a geometric diagram showing the path of the center-point of my heel sheave, and the orientation of that sheave. This diagram is enlarged to six times the scale of Figures 1 and 2.

Referring now to Figures 1 and 2, we see that II is the'main frame of a drill, supported by wheels l2, and during drilling by blocks l3.

The frame It supports a mast l4 (called -derrick in the art), a motor IS, a winch IS, a

spudding gear l1, and associated driving connections, not numbered.

From the winch IS, a rope I8 runs around a heel sheave l9, thence under a spudding-sheave 20, thence over a sheave (not shown) at the top of the derrick l4, thence down to the drilling tools (not shown).

The spudding gear I1 is clutched to and unclutched from a drive connection with the motor l5, by means of a clutch (not shown).

The spudding-sheave 20 is mounted (preferably by means of an offset substantially vertical pivot 2|). on the free end of a spudding-beam 22, which in turn is pivoted on horizontal pivots 23 on the frame ll.

The spudding-beam is rocked up and down by the rotation of the spudding gear l1, acting through pitman 24.

The winch I6 is controlled by means of a conventional drive, clutch, brake, and hand-levers (not shown).

The operation of all these conventional parts will be readily understood.

Heel sheave i9 is free to slide laterally along a floating rod 25, the ends of which are pivoted on swinging brackets 26, which in turn are pivoted on the frame I I. As shown, sheave l slides on rod 25, and turns about that rod as an axis. But, although highly advisable, this is not necessary. Any alternative device, whereby sheave i9 is rotatably mounted, and is free to slide along rod 25, would be sufiicient.

The ivot axes A and B, between the brackets 26 and the frame H, and the pivot axes C and D between these arms and the rod 25, might preferably be so inclined that the plane in which rod 25 moves, will be somewhat upwardly inclined away from the drum it.

My machine was originally built in this manner. But I have found that a cons derable angular departure from the theoretically optimum arrangement is possible without appreciably reducing the effectiveness of my invention. And I have found that the theoretically optimum arrangement unfortunately permits the entire linkage to flop around badly, under the influence of gravity alone, if the rope l8 be slackened. Accordingly I have been forced to compromise between theoretical and practical considerations, by so placing my pivots that rod 25 movesin a horizontal plane. 7

Of course, I could have biased my linkage against flopping by the use of counterweights or springs; but, finding the simpler expedient to be successful in practice, I adopted it Preferably CD should be approximately onehalf AB; and, when CD is parallel to AB, then AC and BD should each form an angle of 45 degrees with AB. But structural conditions frequently prevent the attainment of this optimum, which can be considerably departed from, without appreciably reducing the effectiveness of my invention. With CD more than one-half AB (as shown) I have found that the angle shoul be more than 45 degrees.

Turning now to the geometrical diagram which constitutes Figure 5, we see that that figure represents the right half of the linkage of my invention. AC and AC" represent the two extreme positions of the right-hand bracket 26; and C'D and CD represent the corresponding positions of rod 35. C"0 represents half the path of the center of heel sheave US, which is diagramatically illustrated in one of its positions, properly ori ented. The center-line of the machine is marked with the monogram CL.

By virtue of my linkage, my heel sheave i9 always lies in a position of stable equilibrium in which the lower reach of rope i8 alway lies in a plane perpendicular to the axis'of the drum it, and hence all positions of this rope are parallel to all other positions thereof, and the sheave is always oriented in such a way as to be very nearly in the plane of the two reaches of rope 58.

Furthermore, the slight frictional drag of sheave it on rod 25 is sufiicient to cause it to lag very slightly behind its proper position, thus ensuring a tight lay of the rope on the drum.

By virtue of its swivel, spudding sheave 2E3 always lies in the plane of the two reaches of rope running to it.

Turning now to Figure 4, we see heel sheave l9 on rod 25, the latter being shown in crosssection. A rope guard 27 is also journaled on rod 25 at each side of the sheave. A shoe 28 fits in an opening between ribs 2t and 30 of the guard 2'7. This shoe is constrained by spring 3| and a similar spring on the further side, to bear against the rope, clamping it to the sheave.

The guard 21 is kept from rotating, by beam 32, which slides between projection 33 on the guard and. projection 34 on the shoe. Pivoted on the shoe 23 is a cam 35. By inserting a bar in the socket 36 of this cam, and rotating the rod downward through 90 degrees, the cam will bear against the edges of the guard 21, holding the shoe out of clamping position, and thus permitting the rope to run freely.

Having now described and illustrated one form of my invention, I wish it to be understood that my invention is not to be limited to the specific form or arrangement of parts herein described .and shown, except a limited by my claims.

I claim:

1. A spooling device, comprising: a first sheave; a fixed position drum; a floating sheave; these three elements being adapted to be used in connection with a cable wound around the drum and thence extendin around the floating sheave and thence around the first sheave; means, comprising a rod on which the floating sheave is slidably mounted, constraining the floating sheave to follow such a path that the reach of rope from the drum to the floating sheave will always lie substantially in a plane perpendicular to the axis of the drum, and the floating sheave will always lie perpendicular to its path and substantially in the plane of the two reaches of rope which extend from it; a floating sheave-guard for embracing the floating sheave, and floating therewith; and means to prevent the sheave-guard from rotating with the floating sheave.

2. A sheave-mounting, compr sing: a widespread base; two converging links, each hinged at one end of the base; a rod, materially shorter than the base and hinged at each end to one of the links; and a sheave mounted for lengthwise sliding along the rod.

3. A kinematic mechanism, comprising: a widespread base; two converging links, each hinged at one end of the base; a rod, materially shorter than the base and hinged at each end to one of the links; a movable member mounted to slide along the rod, and to remain at a constant angle thereto; and means to constrain the movable member to occupy predetermined positions in space under respective conditions.

4. A spooling device, comprising: a first sheave, with a substantially horizontal axis; a fixed position drum, with a substantially horizontal axis; a wide-spread base; two converging links, each hinged at one end of the base; a rod, materially shorter than the base and hinged at each end to one of the links; and a sheave mounted for lengthwise sliding along the rod; the plane of the base, the links and the rod, being substantially horizontal; the relative location of the drum, the rod, and the sheave being such that a rope extending from the drum can run first over the sliding sheave and then over the first sheave.

5. A spooling device, comprising: a flrst sheave; a fixed position drum; a floating sheave; a rope, leading from the drum, thence around the floating sheave, and thence around the first sheave;

and means including a floating straight rod on which the floating sheave is slidably mounted, and so restricting and controlling the movement of the floating sheave as to constrain the floating sheave to be in positive equilibrium, under the tension of the rope, when, and only when, the

reach of the rope extending from it to the drum is substantially perpendicular to the axi of the drum; said means also constraining the floating sheave to lie alway substantially in the plane defined by the two reaches of the rope extending from it.

6. A spooling device, comprising: a, first sheave; a fixed position drum; a floating sheave; a rope, leading from the drum, thence around the floating sheave, and thence around the first sheave? and means including a floating straight rod on which the floating sheave is slidably mounted, and so restricting and controlling the movement of the floating sheave as to constrain the floating sheave to be in positive equilibrium, under the tension of the rope. when, and only when, the

, reach of the rope extending irom it to'the drum lies ina plane substantially perpendicularto the axis of the drum.

7. A spooling device. according to claim 1, iur-.

- ther characterized by having: a shoe carried by the sheave-guard: and means to constrain the shoe to yieldably clamp any cable trained about the floating sheave against the floating sheave.

8. A spooling device, according to claim 1, further characterized by having: a shoe carried by the sheave-guard; means to constrain the shoe to yieldably clamp any cable trained about thefloating sheave against the floating sheave; and means for optionally re1iev. ng this constraint.

9. A spooling device, according to claim 1, further characterized by having: a shoe carried by the sheave-guard; means to constrain the shoe to yieldably clamp any cable trained about the floating sheave against the floating sheave; and means for optionally relieving this constraint; said last named means consisting of a cam, pivoted on the shoe, and rotatable to bear against the sheave guard.

10. A spooling device, according to claim 1, further characterized by having: a shoe carried by the sheave-guard; means to constrain the shoe to yieldably clamp any cable trained about the floating sheave against the floating sheave; and meaneior optionally relieving this constraint; said last named means consisting of a cam, pivoted on the shoe, and rotatable to bear against the sheave-guard, and having means. for the attachment of a lever to rotate the cam.

-11. A sheave-mounting, comprising: a widespread base; two converging links, each hinsed at one end or the base; a rod, materially shorter than the base, hinged at each end to one of the links; and a sheave mounted directly on the rod, for rotation about the rod, and for sliding along the TM.

HERBERT W. THORNBURG.

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