US3378304A - Spread-footed three-dimensional headframe and method of erecting same - Google Patents

Description

Apn] 16, 1968 L. BORASIO ET AL 3,378,304

SPREAD-FOOTED THREEDIMENSIONAL HEADFRAME AND METHOD OF ERECTING SAME Filed May 23, 1966 4 Sheets-Sheet 1 FIGL ORNEYS Aprll 16, 1968 L. BORASIO E AL 3,378,304

SPREAD-FOOTED THREE-DIMENSIONAL HEADFRAME AND METHOD OF EREC'IING SAME Filed May 25, 1966 4 Sheets-Sheet 2 FIG. 5.

I INVENTORS LEO BORASIO SVEND A. RONLOV Y CHESTER c. JANCEWICZ 34 FIG. 4. Q z TORNEYS April 16, 1968 L. BORASIO ET AL SPREAD-FOOTED THREE-DIMENSIONAL HEADFRAME AND METHOD OF ERECTING SAME Filed May 25, 1966 FIG. IO,

INVENTORS LEO BORASIO SVEND A. RONLOV CHESTER C. JANCEWHCZ FIG.9.

ATTORNIEYS April 16, 1968 L. BORASIO ET AL SPREAD-FOOTED THREE-DIMENSIONAL HEADFRAME AND METHOD OF ERECTING SAME 4 Sheets-Sheet 4 Filed May 23, 1966 FIG. i3.

INVENTORS LOV JANCEW l CZ ATTORNEYS United States Patent 3,378,304 SPREAD-FOOTED THREE-DIMENSIONAL HEAD- FRAME AND METHOD OF ERECTING SAME Leo Borasio, Denver, Svend A. Ronlov, Englewood, and Chester C. Jancewicz, Lakewood, Col0., assignors to The Stearns-Roger Corporation, Denver, Colo., a corporation of Colorado Filed May 23, 1966, Ser. N 552,020

- 14 Claims. (Cl. 299-18) This invention relates to mine headframes and, more specifically, to a three-dimensional spread-footed headframe along with the method of erecting same.

Deep vertical mine shafts are often sunk in unstable soils that require special treatment in order to prevent cave-ins and other catastrophies from occurring. The accepted practice in such a situation is to freeze the ground immediately adjacent the shaft to stabilize it. This is done by circulating brine in pipes placed in the soil alongside the shaft before the latter is drilled or sunk. The frozen ground, of course, is much more likely to remain in place.

Once the shaft is complete, lined and otherwise shored, the surrounding frozen walls are allowed to thaw out, whereupon, supposedly, the soil returns to its original condition. Unfortunately, it cannot be relied upon to do so and, in fact, it usually assumes a considerably less stable condition following the thaw than it had before it was frozen in the first place.

Upon completion of the shaft, the contractor whose job it is to erect the ore-hoising apparatus above the shaft entrance is, therefore, faced with the prospect of having to do so on soil in worse condition than it was initially. At this stage, he has, undoubtedly, engineered his headframe to suit the soil conditions as they originally existed and any substantial change in these conditions may require considerable redesign.

Another problem of considerable practical importance is that of the inordinate length of time required to get the mine into production. Ordinarily, the shaft contractor must move onto the mine site first, erect the shaft drilling rig and essentially complete the shaft before the contractor whose job it is to build the skip-hoist plant and related facilities can even begin work. In a large-scale operation, say one handling several million tons of ore a year, this procedure may well stretch over four or five years before the mine can be placed in production.

The problems connected with unstable soil conditions could be eliminated or, at least, reduced considerably, if one were to erect the headframe on ground which, while perhaps still unstable, was predictable. In other words, even though special precautions would have to be taken in order to cope with the unstable soil, such as, for example, caisson-mounted footings, the fact that these conditions w re known in advance and would remain substantially constant would enable the contractor to design his structures and the supports therefor to compensate for them.

The timing problem aforementioned is, indeed, a difficult one and about the only prospect for materially re ducing the interval required to get the mine into production would be in the direction of being able to carry out the shaft-drilling and skip-hoist-erection operations more or less simultaneously. Of course, simplified construction methods, pro-fabrication techniques and efficient use of manpower will always result in some time savings; however, about the only way one could expect to reduce the time by say or more, would be to overlap the drilling and plant-erection phases to a considerable extent.

It has now been found in accordance with the teaching of the instant invention that solutions to the foregoing problems can, in fact, be achieved. To do so involves 3,378,304 Patented Apr. 16, 1968 the use of a unique headframe structure, together with a novel sequence of erecting same such that the drilling operations may proceed simultaneously, in fact, substantial savings in the cost of drilling the shaft can be realized because permanent portions of the skip-hoist headframe can be used as the super-structure from which the drilling apparatus is suspended, thus eliminating the need for a special superstructure for this purpose that has to be removed upon completion of the shaft.

Specifically, a spread-legged space frame is erected first over the site of the shaft with the ground supports therefor spaced a considerable distance from the area that will have to be frozen. The footings supporting the legs of the space frame include jacks by which each leg may be adjusted independently of the others to correct for any heaving or settling that may occur. Most important, however, is the space surrounding and overlying the entrance to the mine shaft'is left completely unobstructed. Thus, the shaft can be sunk by conventional methods without regard to the presence of the space frame or, preferably, the latter can be used as the superstructure supporting the drilling apparatus.

One of the most unique features of the invention, however, resides in the sequence of erecting the skip-hoist headframe. With the space frame in place and the shaft being drilled therebeneath, erection of the upper portion of the skip-hoist headframe proceeds uninterrupted using the shelf or floor of the space frame as a foundation positioned one hundred feet or so above ground level. The upper portion of the headframe houses the hoisting motors, the rigging, guidance apparatus, retardation equipment, service decks and the like, most of which can be installed while the shaft is being sunk. The lower portion of the skip-hoist headframe, on the other hand, is primarily structural steel providing guideways for the skips and is, therefore, largely devoid of the complex equipment that is so time-consuming to install. For this reason, once the shaft is completed and the drilling apparatus detached from the space frame, it becomes a simple matter to complete the tower by erecting the lower portion thereof.

One other noteworthy feature of the headfrarne is the provision of vertically-slidable joints between the upper and lower portions thereof which permit the upper half to be aligned by means of the footing jacks somewhat independently of the lower portion. This feature also permits the lower portion to settle or heave independent of the upper portion.

fit is, therefore, the principal object of the present in vention to provide a novel and improved spread-footed three-dimensional headframe for deep vertical shaft mines and the like.

A second equally important object is the provision of a unique sequence for erecting the headframe which permits the shaft sinking operation to take place simultaneously with erection of the upper portion thereof.

Another object is to provide a spread-legged space frame whose ground supports are located remote from the freeze zone required to stabilize the shaft walls.

Still another objective of the invention herein disclosed and claimed is to erect a spread-legged space frame over the site of the mine shaft which can function as both the supporting structure for the shaft-digging apparatus and the skip-hoist plant.

An additional object is to provide a method and apparatus for mining deep vertical shafts that enables the mine to be placed in operation considerably faster than was heretofore possible.

Further objectsare to provide a mine skip headframe and method of erecting same that are efficient, extremely versatile, less costly, fast, relatively simple, and ideally suited for use on unstable soils.

Other objects will be in part apparent and in part pointed out specifically hereinafter in connection with the description of the drawings that follow, and in which:

FIGURE 1 is a somewhat diagrammatic front elevation of the spread-footed headframe of the present invention;

FIGURE 2 is a similar side elevation thereof;

FIGURE 3 is a top plan view of the space frame to an enlarged scale, portions of which have been broken away to conserve space;

FIGURE 4 is a further enlarged fragmentary section taken along line 44 of FZGURE 3 through one of the corners;

FIGURE 5 is a fragmentary sectional detail showing the slip joint that interconnects the lower portion of the headframe to the platform of the space frame so as to permit relative vertical movement therebetween;

FIGURE 6 is a fragmentary longitudinal section through one of the space frame legs taken along line 6-6 of FIGURE 7;

FIGURE 7 is a fragmentary section taken along line 77 of FIGURE 6 showing the means for adjusting each leg relative to its footing;

FIGURE 8 is a fragmentary horizontal section taken along line 8--8 of FIGURE 7;

FIGURE 9 is a front elevation of the space frame alone;

FIGURE 10 is a front elevation showing the upper portion of the headfrarne erected on the platform or deck of the space frame;

FIGURE 11 is a front elevation similar to FIGURE 1 showing the lower portion of the headfrarne added to the FIGURE 10 structure;

FIGURE 12 is a view similar to FIGURE 9 but showing the ground in section so as to reveal the location of the mine shaft and surrounding freeze zone in relation to the footings supporting the space frame;

FIGURE 13 shows the space frame in place with the conventional independent shaft-drilling apparatus in place therebeneath;

FIGURE 14 is a view similar to FIGURE 13 except that a modified shaft-drilling apparatus utilizing the space frame as a supporting structure has been substituted for the conventional driiling apparatus; and

FIGURE 15 is a fragmentary detail similar to FIGURE 4 showing a pivotal connection by which the lower half of the tower and the shaft-drilling apparatus can be hung from the space frame platform.

Before commencing with a detailed description of the drawings, it should be pointed out that no attempt has been made to illustrate the detailed framework of the headframe which, of course, is braced throughout and comprises an extremely complex structure. The same is true of the mine skips, hoisting apparatus, retardation equipment, elevator shaft, control apparatus and all of the other accessory equipment which goes into a modern skip-hoist tower. While some of these features have been illustrated more or less diagrammatically, the purpose in doing so is to locate them within the headframe and no novelty is predicated upon these features per se. The main novelty resident in the headframe is brought about through the use of the space frame concept and other well-known skip-hoist towers could readily be adapted for use therewith. The same is true of the equipment housed in the headframe, that which is illustrated being merely representative of many such pieces of equipment that could be used to take ore from the mine.

Accordingly, with specific reference initially to FI URES 1 and 2 of the drawings, reference numeral 10 has been employed to designate in a general way the so-called space frame which includes an elevated platform 12 upon which is erected approximately the upper half 14 of the skip-hoist tower that has been similarly referred to broadly by reference numeral 16. The lower half 18 of the tower 16 is independently supported beneath platform 12 of the space frame and is connected thereto in aligned a relation to the upper half 14 by slip-joints that will be described in more detail presently.

The upper half 14 of the tower has a heavy structural machinery deck 20 that carries the hoisting motors (not shown) and the friction wheel 22. The continuous-loop ioist ropes 24 are reaved over the top of the friction wheel and down across deflection sheaves 26 mounted on deck 28 directly beneath deck 20. A pair of ore skips 30, only one of which has been shown, are attached to the hoist ropes 24 in a more or less counterbalanc ng relation to one another. One of these skips is returning to the bottom of the shaft 32 (FIGURE 12) empty, while the other fully loaded one is rising into the headframe to a point at which it discharges into an ore chute 33. Ore hoists of the above type employing a friction wheel are commonly-known in the art as a Koepe hoist in honor of the inventor thereof and they are widely used throughout the world.

The space frame It} forms a part of the headframe 16 which also includes the upper and lower halves (I4, 18) of the tower. This space frame, in the particular form shown, has four legs 34 that extend downwardly and outwardly from the corners of rectangular platform 12 to footings 36 spaced well outside the frozen zone 38 surrounding the mine shaft 32 as indicated in FIGURE 12. Three or more legs may obviously be employed to support the deck of the space frame and still accomplish the same function. Also, while the space frame is ideally suited for use in those situations where unstable solls are present that must be frozen adjacent the mine shaft and rethawed upon completion thereof, it is equally useful on good firm ground to provide a considerable unobstructed area adjacent the shaft site that allows work to proceed in connection with sinking the shaft while a goodly portion of the tower is being erected as will be seen presently. For example, towers around 100 feet high may have the footings 36 located as much as 80 feet apart, whereas, a 200 foot tower can accommodate footing spacings 120 feet or more apart. Ordinarily, the freeze zone does not extend out from the center of the shaft much more than about 70 feet, which means that the footings can be laid in virgin ground unaffected by freezing and thawing.

Next, with reference to FIGURES 3-8, inclusive, some of the more significant details of the space frame 16 will now be set forth. As illustrated, each of the legs 34 has a hollow triangular cross-section that steadily increases in area from the footing up to the point at which it is joined to corner-forming element 40. As seen in FIG- URE 6, the specific shape is that of an isosceles triangle wherein the equal sides 42 meet at approximately a right angle and a reinforcing web 44 extending perpendicularly from the midpoint of the base 46 to the apex of the right angle. Triangular stiffeners 48 (FIGURE 7) are employed at various levels to reinforce the legs. Once again, no particular novelty resides in the leg design and many other geometrical sections would function just as well for this purpose.

As seen in FIGURE 7, the footings 36 each comprise a sunken poured-concrete block having an L-shaped rib '50 bordering the two outside margins of horizontal platform 52. These ribs cooperate to retain the box-like appendage 54 that forms the foot of each leg 34. Resting upon platform is a bearing plate 56 that, in turn, mounts a pair of jack pads 53 that fit up into corresponding openings 60 in the foot 54 of each leg. Mounted atop each of these pads is a heavy-duty jack 62 that presses up against the top 64 of the box-like foot 5-4 and provides means for raising and lowering each leg independently of the others. The use of two jacks on each leg permits raising or lowering the feet while shims are inserted. Extending transversely of each leg above the point at which the jacks contact the top 64 of the foot 54, a vertical stiff-back 66 is positioned as shown. This leg adjustment feature is important in that it allows the operator to maintain platform 12 of the space frame level at all times despite any settling and heaving that may take place at the footings. By keeping platform 12 level, the upper half 14 of the tower 16 that rests entirely thereon may, likewise, be kept in proper alignment with the mine shaft and this, of course, is absolutely essential to proper operation of the skip-hoist.

The corner-forming element 40 of each leg 34 is most clearly revealed in 'FLIGURES 3 and 4 to which specific reference will now be made. Plates 66 form coplanar extensions of plates 42 that define the outer skin of the legs. These plates have a curved inside edge 63 that merges toward its upper terminus in a short horizontal section 70. The outside edge thereof 72 is upwardly and inwardly inclined as shown in FIGURE 3 at the same inclination as the legs 34. The top edge 74 is horizontal, whereas, the free end 76 terminates in a step-cut edge 78.

The bottom of the corner-forming element 40 comprises a curved plate 80 (FIGURE 4) that adjoins the inside edges 68 of the side plates 66, the top edge of plate 46 on the back of the leg, and the bottom edges of vertical partition plates 82, 84 and 86 that lie in spaced parallel relation to one another outwardly of step-cut edge 78. The top plate 88 is generally triangular and the latter elements cooperate with the connecting beams 90 to detfine a square opening 92 (FIGURE 3) in the center of platform 12 that has truncated corners. Still another partition plate 94 is located near the bottom end of each corner element in perpendicular relation to side plates 66. A stiff-back 96 extends from this partition plate to the underside of the top plate 88. The stepcut free ends 76 of each corner element 40 are covered by plates 98, 100 and 102 as shown in FIGURE 4.

The connecting beams or girders 90 have both extremi ties shaped to provide inverted stepcut ends 104 that mate with the corresponding step-cut ends of the corner forming elements 40. The ledges 106 (FIGURE 4) provided by the step-cut ends of the corner members, of course, support the girders while the latter are being welded in place. The net functional effect of girders 90 is to form keystones bridging the adjacent legs to form an arch.

In FIGURES 4 and 5, it can be seen that the underside of each corner-forming element 40 is provided with one or more collars 1&8, only one of which has been shown, that receive the uprights 110 of the lower section 18 for vertical sliding movement. This slidable connection enables the operator to raise and lower the corners of space frame platform 12 without disturbing the lower groundanchored section 18 of the tower. Such adjustment is, of course, desirable in order to maintain the upper half of the tower perfectly aligned with the shaft 32.

Next, with reference to FIGURES 9l5, inclusive, the sequence of erecting the space frame, sinking the shaft and erecting the tower will now be set forth in detail. The first operation is to set the footings 36 in equi-angularly spaced relation around the center of the proposed shaft. Next, one of the legs 34with the corner element 40 already attached thereto is raised on its footing into approximate position and held in place by suitable temporary bracing. The same procedure is followed to erect one of the legs adjacent to that already in place and then the girder 90 interconnecting the two legs is fastened to the free ends thereof to complete one arch.

From this point, either one of two alternate procedures may be followed. The first of these is to erect the other two legs and complete a second arch opposite the first before bridging the two arches thus formed with the connecting girders 90. A second approach, obviously, is to erect the third leg and bridge to the completed arch before raising the fourth leg into place. The latter approach is, perhaps, the simpler of the two because the space frame structure becomes successively more rigid thus cutting down on the bracing required as each step is completed. Still another approach is to fabricate both arches on the ground and raise same into place to be attached together by the connectors, provided, of course, that the requisite crane capacity is available. All three of these procedures are completely practical, however, and result in the same finished structure. When complete, the space frame will appear as in FIGURE 9. It will be observed that the area immediately adjacent the site of the proposed shaft is completely unobstructed as is the space thereabove for a considerable distance.

Now, if the shaft-drilling contractor elects to sink the shaft 32 using a conventional drilling rig 112, he merely positions same as shown in FIG. 13 underneath the platform and between the legs of the space frame, provided it has not been placed in position previously. Such a groundsupported rig requires considerable lateral deflection bracing 114 to prevent the tower from tilting as force is applied to haul-line 116. The compression loads on the drilling rig tower are also considerable and it mus-t, therefore, be of heavy braced construction.

The better practice would seem to be that illustrated in FIGURES l4 and 15 when the modified drilling rig tower 112m is hung from the platform 12 of the spaced frame. FIGURE 15 shows a clevis 118 fastened to the underside of corner-forming element 40 to which the uprights 120 of the sheave frame 122 could be pivotally attached. The main loads impressed upon the drilling rig would thus be carried by the space frame permitting a lighter rig to be used and eliminating the need for lateral bracing 114.

At this point, it would the well to point out in connection with FIGURE 15 that the lower half 18 of the headframe tower 16 could, likewise, be hung from the platform 12 of the space frame. If this were done, the slip-joints on the uprights would be relocated on the ground.

Once the drilling rig is in place, the drilling contractor can proceed to lay in the pipes that will border the shaft and carry the brine used to produce the frozen zone bordering same as shown in FIGURE 12 preparatory to sinking the shaft within the zone thus defined. Simultaneously with the sinking of shaft 32, the upper half 14 of the skip-hoist tower 16 may be erected on top of space frame platform 12 as indicated in FIGURE 10. Literally, therefore, the top half of the tower is built before the bottom half using the space frame platform as an elevated foundation therefor. It is entirely possible that much, if not all, of the operating equipment housed in the upper half of the tower can be placed into position while the shaft is being completed. In any event, much of the most complicated and time-consuming work associated with erection of the hoisting plant which heretofore had to be delayed pending completion of the shaft can now be carried out simultaneously therewith.

The final steps in the procedure are, of course, to remove the drilling rig and erect the lower half of the skiphoist tower as in FIGURE 11. This as a comparatively simple operation because the lower half of the tower con sists primarily of guideways to define an elevator shaft for the skips. About the only complex equipment housed in this section of the tower is the ore chute and it is simple compared with the hoisting apparatus found in the upper half.

Having thus described the several useful and novel features of the spread-footed three-dimensional headframe and method of erecting same that constitutes the instant invention, it will be apparent that the many worthwhile objectives for which they were developed have been achieved. Although but a few alternative embodiments of i the invention have been illustrated and described herein,

we realize that certain changes and modifications therein may well occur to those skilled in the art within the broad teaching hereof; hence, it is our intention that the scope of protection afforded hereby shall be limited only insofar as said limitations are expressly set forth in the appended claims.

What is claimed is:

1. In a mine headframe, at least three ground-anchored footings spaced radially outward from the centerline of the mine shaft and arranged in substantially equi-angularly spaced relation to one another, an upwardly and inwardly inclined leg resting on each footing, means bridging the upper extremities of adjacent legs cooperating therewith to define a continuous series of flat-topped arches and an elevated horizontal platform having an open center, and a tower erected atop the platform adapted to house a mine skip-hoist and including a vertically-disposed elevator shaft therefor.

2. The headframe as set forth in claim 1 in which: means for sinking a mine shaft are located beneath the platform.

3. The headframe as set forth in claim 1 in which: a continuation of the skip-hoist tower is connected to the platform bridging the space between the latter and the ground.

4. The headframe as set forth in claim 1 in which: jack means are interposed between each footing and the leg resting thereon adapted upon actuation to adjust said leg independently of the others so as to level the platform and maintain the vertical alignment of the tower erected thereupon.

5. The headframe as set forth in claim 2 in which: the means for sinking the mine shaft is suspended from the platform.

6. The headframe as set forth in claim 3 in which: that portion of the tower located beneath the platform is suspended therefrom.

7. The headframe as set forth in claim 3 in which: that portion of the tower located beneath the platform is ground-supported, and in which means comprising slipjoints adapted to permit limited vertical relative movement between said lower tower portion and the platform provide the connection therebetween.

8. The headframe as set forth in claim 4 in which: the jack means includes two jacks under each leg which are capable of holding the latter in elevated position while shims are inserted therebeneath.

9. The improved method for sinking a vertical mine shaft and erecting a headframe thereupon adapted to house a skip-hoist which comprises the steps of: erecting an elevated horizontal platform over the site of the mine shaft supported upon downwardly and outwardly divergent legs, erecting the upper portion of the headframe atop the elevated platform while simultaneously sinking the shaft thereoeneath, and erecting the lower portion of the headframe underneath the platform following completion of the mine shaft.

10. The improved method for sinking a mine shaft and erecting a headframe thereon as set forth in claim 9 which includes the steps of suspending the shaft-drilling apparatus from the platform and subsequently replacing same with the lower headframe portion.

11. The improved method for sinking a mine shaft and erecting a headframe thereon as set forth in claim 9 which includes the step of permanently hanging the lower portion of the headframe from the platform.

12. The method for sinking a mine shaft and erecting a headframe thereupon as set forth in claim 9 which includes the steps of freezing the ground in an area immediately adjacent the mine shaft while sinking same and locating the feet of the platform legs beyond said frozen zone.

13. The spread-footed space frame for use as a foundation for the upper portion of a mine skip-hoist tower which comprises: at least three ground-anchored fO ting arranged in equi-angularly-spaced relation around the site for a mine shaft, an upwardly and inwardly inclined leg resting atop each footing, beam means bridging the space between adjacent legs and cooperating therewith to form a continous series of flat-topped arches and an elevated horizontal platform with an opening in the center thereof, and platform leveling means interposed between each footing and the leg resting thereon adapted upon actuation to raise and lower said leg independently of the others.

14. The spread-foot space frame as set forth in claim 13 in which: the platform-leveling means comprises a pair of jacks, each of said jacks being capable of lifting the leg otf of the footing for the purpose of inserting shims.

References Cited UNITED STATES PATENTS 766,132 7/1904 Baggaley 61-40 1,100,622 6/1914 Rowley 61-40 FOREIGN PATENTS 892,734 5/1944 France. 1,017,115 10/1957 Germany.

ERNEST R. PURSER, Primary Examiner.

UNITED STA'TES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,378,304 April 16, 1968 Leo Borasio et a1.

It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

In the heading to the printed specification, lines 5 to 7, "assignors to The Stearns-Roger Corporation, Denver, Colo., a corporation of Colorado" should read assignors, by mesne assignments, to United States Borax G Chemical Corporation, a

corporation of Nevada Signed and sealed this 28th day of October 1969.

(SEAL) Attest:

Edward M. Fletcher, J r.

Attesting Officer Commissioner of Patents WILLIAM E. SCHUYLER, JR.

Claims (1)

1. 9. THE IMPROVED METHOD FOR SINKING A VERTICAL MINE SHAFT AND ERECTING A HEADFRAME THEREUPON ADAPTED TO HOUSE A SKIP-HOIST WHICH COMPRISES THE STEPS OF: ERECTING AN ELEVATED HORIZONTAL PLATFORM OVER THE SITE OF THE MINE SHAFT SUPPORTED UPON DOWNWARDLY AND OUTWARDLY DIVERGENT LEGS, ERECTING THE UPPER PORTION OF THE HEADFRAME ATOP THE ELEVATED PLATFORM WHILE SIMULTANEOUSLY SINKING THE SHAFT THEREBENEATH, AND ERECTING THE LOWER PORTION OF THE HEADFRAME UNDERNEATH THE PLATFORM FOLLOWING COMPLETION OF THE MINE SHAFT.

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