US2954131A - Oil well hoist - Google Patents

Description

Sept. 27, 1960 Filed Aug. 29, 1957 A. H. WILKINSON OIL WELL HOIST 2 Sheets-Sheet 1 v Sept. 1960 A. H. WILKINSON 2,954,131

011. WELL nozs'r INVENTOR.

'5 BY MW/ v i X OIL WELL HOIST Alvin H. Wilkinson, Talala, kla., assignor to Cabot Slhops, Inc., Boston, Mass., a corporation of Massac usetts Filed Aug. 29, 1957, Ser. No. 681,056

2 Claims. (Cl. 214-25) This invention comprises a new and improved hoist for oil well service, particularly useful for running rods, pipe or tubing into and out of oil Wells.

Hereto'fore the industry hasbeen served with hoists having a single traveling pulley which lifts the load while ascending and then descends by gravity, During the descent of the pulley the source of power is not being utilized and a period of time is consumed which in some instances is greater than the length of the hoisting period. The hoist of the present invention includes in its organization an upright support or mast carrying two travelling pulleys operated by power in such a manner that one pulley is ascending while the other is descending with the result that the descending pulley will be in position for latching onto the load as soon as the ascending pulley reaches its maximum height. The hoist of this invention, therefore, presents a decided advantage'in efiicient operating speed over hoists heretofore available.

In order to locate either of the traveling blocks in line with the center of the well, the improved hoist includw a carrier member or crown block movably supported on the mast and having separate guide pulleys for leading hoisting cables in different paths to traveling pulleys suspended by each cable from the carrier, the

States carrier being movable upon the mast to bring either one of the traveling pulleys into the desired predetermined position.

As an optional feature power operated mechanism for swinging or rocking the carrier member is located upon the mast under remote control thus contributing to the convenient operation of the hoist.

As herein shown the two cables by which the traveling pulleys are suspended are oppositely wound upon a hoisting drum which is provided with reversible power operating means and with -a brake by which the drum may be arrested with either of the traveling pulleys at its maximum height. It will therefore be seen that one or the other of the traveling pulleys is always in position to take on the current load without any delay.

The employment of a single hoisting drum for both cables results in important structural advantages such as reduction of weight and simplification of the entire mechanism. For example, the friction drive clutch as heretofore used is not required since there is no necessity of providing a free turning drum as found in hoists Where gravity is relied on for part of the operation. Moreover, the drum can be installed in line with the other mechanism eliminating the necessity of a right angle gear box.

A further advantage of the improved hoist is that the post or derrick always occupies a vertical position thus permitting the load-to be carried without the development of bending stress and consequent heavy structure. Where weight reduction is paramount as in portable units, the power unit may be substantially reduced in size and still maintain a speed of operation in excess of conventional practice; also since the engine will be under load nearly twice as much of the time as heretofore, its size may be reduced Without any sacrifice in operating time.

2,954,131 Patented Sept. 27, 1960 'ice These and other features of the invention will be best understood and appreciated from the following description of two preferred embodiments thereof selected for purposes of illustration and shown in the accompanying drawings in which: I

Fig. 1 is a view in elevation of the complete unit,

Fig. 2 is a top plan view,

Fig. 3 is a fragmentary view in elevation of a modified construction, and r Fig. 4 is a fragmentary view in elevation of another modified construction.

As shown in Fig. 1 the entire unit is mounted on a base 10 upon which is erected an upright support in the form of a post or mast 11. This rests in a socket member 12 and may be maintained in a vertical position by suitable guy ropes not shown. At the top of the post is a fixed top plate 12 and upon this rests a carrier member or crown block 13 pivotally mounted to swing about the vertical axis of an upwardly projecting shaft 14. The crown block 13 may be swung by pulling one of the travelling pulleys laterally in the desired direction at the ground level.

The crown block 13 has. diverging end sections as best shown in Fig. 2 and at the extremity of these sections are mounted guide pulleys 15, 16, 17 and 18. These pulleys are radially disposed with respect to the axis of the shaft 14 and arranged to guide separate cables in paths which intersect in the axis of the shaft 14. Guide rolls are provided in this shaft at different elevations so that cables 21 and 22 may pass freely over the guide pulleys 16-18 and the guide pulleys 15-17.

A traveling pulley 19 is, suspended in the cable 22 beneath the guidepulley 17 and a travelling pulley 20 is suspended in the cable 21 beneath the guide pulley 18. The cables 21 and 22 are wound oppositely upon a hoisting drum 23 mounted in suitable bearings upon the base 10, and it will be apparent with this arrangement that when the pulley 19 is being raised the pulley 20 is being lowered and vice versa.

The drum 23 is provided at one end with a band brake which operates in either direction of drum rotation. At the other end the drum is connected by a sprocket and chain 25 to a driving sprocket on the end of a torque shaft 26.

The shaft 26 may be operated from a gasoline engine or motor 27 through a speed reducer or torque converter 28, a reversing gear 29 and a transmission unit 30. The reversing and transmission units are under manual control so that the speed and direction of rotation of the drum 23 may be varied and adjusted to current conditions 0 work.

The angular movement of the crown block 13 about the axis of the shaft 14 which as herein shown is in line with the axis of the post 11 is such that either pulley 17 or 18 may be moved into position in line with the center of the well which is indicated in Fig. 1 by the dotand-dash line 31'. In Fig. 1, for example, it may be assumed that the traveling pulley 19 is ascending in the line 31 and the pulley 2t} descending from the guide pulley 18 in a position offset from the line 31 sufiiciently that the two pulleys will clear each other in passing. For lifting the traveling pulley 19 it will be seen that the drum 23 must be rotated in clockwise direction as seen from its right hand end in Fig. 1.

In Fig. 3 is illustrated a modified structure in which two running pulleys are operated in the same manner as those described in connection with the construction of Figs. 1 and 2 although a somewhat different means is shown for shifting the pulleys to and from the center line of the well.

As shown in Fig. 3 the post 34 carries at its upper end an overhanging top plate 35 to which is fastened a stationary forked head 36. Between the-forks of this-head is pivotally mounted a triangular rocker 37 which is arranged to swing on a horizontal pivot pin 33 extending between the forks. Guide pulleys 39 and 40 are mounted ...in the. rocker 37 being spaced. about.60? apart about ,the aXis of the pin 38.

The head 36 carries a parrot .g'uide pulleys 41 which .are located side by side and freely rotatable about an axis located above and slightly to the rear of the'pivot 7 pin 38and in the rear portion of the head are mounted another pair of guide pulleys '42. A hoisting cable 43 is guided over one of the pulleys 42, one ofthe pulleys 41 and the pulley 39 below which is suspended the traveling pulley 46. Another hoisting cable 44 is fastened over the other guide pulley 42, the other guide-pulley 41 and the pulley. 40 ofthe rocker'37.. Below this is suspended the traveling pulley 45. In Fig. 3 the rocker 37 is shown in neutral position with both of the traveling the forked head 36 and connected through a piston rod to an arm 48 shown as projecting upwardly from the rocker 37 above the pivotpin 38. Fluid pressure may be admitted to one end or other ofthecylinder 47 accord-- ing to which of the two traveling pulleys it is desired to locate in line .with the well. The. dotted line position shows the rockeras swung in a counter-clockwise direction sufficiently to bring the guide pulley 39 and ,the

traveling pulley 46 into line with the well. It will be understood that the guide pulleys shown .in Fig. 3 are offset transversely so that the separate hoisting cables 43 and 44 will run freely without interference.

While my novel well hoist is herein shown as having a single pole or fabricated mast it is contemplated that a double pole mast 50 may be employed desired as shown in Fig. 4 and in that case the head 52 would bridge the two component poles with the top plate 35 mounted on a saddle 54. The forked head 36 with the rocker 37 being supported by the top plate 35 so that the traveling blocks will hang vertically when the mast is tilted at varying degrees to provide clearance between its base and the well.

Having thus disclosed my invention and described in detail certain preferredernbodiments thereof, I claim as new and desire to secure by Letters Patent:

A; wellhoist.comprisingan upright posthaving a "fixed. top plate, a triangular. rocker suspendedby one corner thereof from said top plate for swinging about a horizontal axis, apulley mounted ateach of the remaining two corners of said rocker, cooperating guide pulleys mounted in offset. relation upon the fixed top plate, power mechanism engaging with said rocker for swinging the rocker from one position to another, and separate cables running over the offset guide pulleys and the respective pulleys mounted on the rocker.

' 2. A well hoist comprising a post having a fixed top plate, a forked head secured to said plate and overhanging the plate at both ends, a triangular rocker suspended by one corner thereof between the forks at one end of the head,,said rocker being adapted. to swing about a horizontal .axis, a pulley mounted at each of the remain ing two corners of said rocker, cooperating guide pulleys mounted in oifset relation upon the fixed plate, power mechanism mounted on the top plate for swinging the rocker from one position to another, and separate cables running overv the ofiset guidepulleys of the respective pulleys mounted on the rocker.

References Cited in the file of this patent UNITED STATES PATENTS 198,895 Meh-arry Jan. 1,1878 225,330 Box Mar. 9, 1880 479,730 Anderson July 26, 1892 2,226,947 Sheldon Dec. 31, 1940 2,342,139 Gleason Feb; 22, 1944 2,644,666 Johnson July 7, 1953

Images