US3074564A

US3074564A - Mast extension jib

Info

Publication number: US3074564A
Application number: US92672A
Authority: US
Inventors: William A Davis; J Spencer Van Alsburg
Original assignee: Chicago Bridge and Iron Co
Current assignee: Chicago Bridge and Iron Co
Priority date: 1961-03-01
Filing date: 1961-03-01
Publication date: 1963-01-22
Anticipated expiration: 1980-01-22

Description

Jan. 22, 1963 W. A. DAVIS ET AL MAST EXTENSION JIB Filed March l, 1961 SSheets-Sheet l 5' Sheets-Sheet 2 w. A. DAvls ET AL MAST EXTENSION JIB Jan. 22, 1963 Filed March 1, 1961 5 Sheets-Sheet 3 W. A. DAVIS MAST EXTENSION JIB Jan. 22, 1963 Filed March l, 1961 vUnited States Iilinois Filed Mar. 1, 1961, Ser. No. 92,672 6 Claims. (Cl. 212-64) This invention relates to an apparatus -for facilitating the erection of elevated structures. It more particularly relates to an extension jib derrick mounted atop the mast of the erection apparatus.

There has been developed a method of erecting elevated structures supported on one or more columns employing a gin pole or mast atop which is mounted a derrick device for lifting the structural elements for placement, wherein the gin pole is jumped upward to succeeding elevations as the work progresses until a predetermined height is reached and the central column is then used to support a derrick with a rotatable boom to nish hanging the steel in the upper portion of the tank. A mast and mast support system employed in this construction facility is described and claimed in U.S. Patent 2,754,012.

It is known in the art that a load on the boom portion of the mast-mounted derrick shown in the aforementioned patent induces a stress due to bending in the mast-mounting portion of the derrick which is proportional to the radius of the boom. According to the instant invention there is provided a mast extension jib derrick which places only vertical loading on the mast and greatly increases the lifting capacity of the derrick as well as the size and type of structures on which the aforementioned gin pole type of construction facility can be used.

In the drawings:

FIGURE 1 is a diagrammatic illustration of one embodiment of the extension ji'o derrick of this invention mounted on an illustrative gin pole;

FIGURE 2 is another embodiment of the extension jib derrick;

FGURE 3 is a schematic showing of one embodiment of the derrick device wherein the lower anchor system for the jib stay is replaced by a counterweight;

FIGURE 4 is a cross-sectional view of the mast portion illustrating the means for preventing vertical sway of the mast assembly and showing the attachment of the back stay to a mast jumper;

FIGURE 5 shows an alternative rigging arrangement for use on the jib derrick shown in FiGURE 1;

FIGURE 6 shows an alternative rigging arrangement for use on the extension jib derrick illustrated in FIG- URE 2;

FIGURE 7 illustrates an adjustable structural member connection between the jumper support and jib stay connection point.

Referring to FIGURE l, the preferred embodiment of the invention is shown in elevation. The illustrative construction facility comprises the removable support 10 which is adapted to be temporarily secured to the central column C of an elevated structure being erected. The bottom jumper mast support 16 for the mast comprises a tubular member il through which extends a mast l2. 'Die tubular member il is provided with holes i3 matching corresponding holes in the mast i2 through which bolts 14 are passed to secure the mast to the support. A pair of straps 15 extend outwardly from the tubular member il near one end thereof and a similar pair of straps '16 extend outwardly from the other end of the member 11. Secured to the outer ends of each of the straps by means of hinges i7 are apertured plates i8, each of the plates being provided with an opening 19 therein to receive an apertured lug 2d welded to the column C.

Tapered pins 21 are passed through the holes in the lugs 20 to secure the member il to the column. To prevent side sway in the bottom mast support it), angle irons 22, as shown in FiGURE 4, are bolted or otherwise secured between each pair of legs 1'5 and 16 and to each angle iron 22 a coupling device 23 being so formed as to provide in cooperation with the angle iron 22' flange a pair of openings 24 and 25 is fastened to angle iron 22 by welding, bolting or the like. The openings 24 and 25 are adapted to register with similar openings 26 and Z7 formed by cooperation with the wall of column C and a corresponding coupling device 28 welded to the column C. The coupling devices are joined together yby pin 29.

Secured to the side of the member 11 adjacent its lower end is a sheave 30 adapted to receive a cable 3'1 passing thereover and thence downwardly around another sheave 32 secured to the bottom of the mast 12. The cable then passes upwardly and is secured to an anchor fitting 33 mounted, for example, on the lov/er end of the member 11.

Also a part of the mast support system is the upper jumper mast support 34 adapted to receive the mast 12 therethrough and provided with straps 35 similar to the

straps

15 and 16, each strap being provided with a hinge 36 at its outer end and secured to an apertured plate 37. The aperture in the plates 37 are adapted to receive apertured lugs 38 therethrough, the lugs being welded to the column C. A pin 39 may be inserted through the lug 38 to secure the plate and hence the member 34 to the column. A coupling device 4d, as previously described, is provided on the member 34- to hold that member against side sway. The lower end of the tubular member 34 is provided with a flange 42 adapted to rest against the corresponding ange 43 provided on the upper end of the member 11. The member 34 is also provided with a second tlange 44 adjacent its upper end against which a pin or bolt 45 extending through an opening 46 in the mast can rest to secure the mast against vertical movement when supported solely by the member 34- as hereinafter described.

To carry out the instant invention, the upper portion of mast 12 is provided with a derrick mounting section 50 consisting of a cored cylindrical socket 5l into which rits the pin 52 of the jib derrick yoke to provide a swivel mount to permit horizontal rotation for the jib derrick. Yoke 53 is a clevis-like arrangement having spaced upwardly extending arms 54 which straddle the connection point 55 of the jib derrick which is shown generally at 55. The truss framework of the jib derrick consists of a chord member 57 rigidly braced by spacer strut 5S and brace rods 59 and 6d which respectively connect the spacer strut 58 with the load end and anchor end of chord member 57. An axle 6i passes through the arms 5d of bracket base 53 and the intermediate connection point 55 on chord member 57 in order that the jib derrick 56 can be pivoted in its vertical plane. Rotatable sheave 62 is mounted at the load end of the chord member 57 of the jib derrick by means of pin 63. A direction-changing sheave 64 is mounted on chord member 57 adjacent the connection point '55 by means of bracket 65. At the anchor end of jib derrick 55 there is pivotally connected one end of ji'o stay 65. Jumper support l@ is provided with spaced mounting brackets 67' and 63' into which are fitted joint connections 69 and 7d formed by cylindrical hinge pins 7l and 72 which allow tree horizontal rotation of the jib derrick and

connector pins

73 and 74 which allow freedom from binding due to misfabrication, and vertical adjustment oi the anchor system. One end of structural member 75 is connected to joint connector 69 while the corresponding end of structural member-76 is connected to joint connector 7d, The other end of the structural members 75 and '76 converge to a common 3 point where they are interconnected. A jib stay 66 is pivotally connected by link connectors 78 and l79 between the anchor end of the jib derrick 56 and the connecting point of the

structural members

75 and 76 to restrict vertical rotation of the jib derrick 56.

Lifting hook 80, located directly overthe centroid of the central column C transfers the load lviacable 81 over sheaves V62 and 64|' to a lifting'winch, not shown, located on lthe ground.

By employing the jib derrick of this invention, all the loading on the mast 12 is vertical'an'd there is'no eccentricity developed with this configuration from which bending stresses in the mast will result. For exarnple, -the 'conventional'boom and mast' arrangement as shown in U.S. Patent 2,754,012 can'lift, as a maidmunnja piece 6 feet in diameter and 16 feet long, and weighing' about 4,760 lbs. V-'Ihe mast extension herein described is not limited dimensionally to any sie orweight lift buffer a corresponding sized jib derrick, constructed infaccor'da'n with this'invention, a lift of 10,00() lbs. Acan be triade.

' Although'the preferred embodiment 'of jib'derrickis Y shown in FIGURE l, there are a variety of modifications sof this Astructure Vwhich can be made. For simplicity;'tlie same numbers as used above will -be employed in describing equivalent membersrin the fllowing variations. For example, thedirection-changi'ng shear/e643` as Ish'ivn in FIGURE 5, can be placed at the'ancho'r vend of the jib derrick 56, or structural members 77 'or 78 liii-the lwer anchor system, as vshown in FIGURE 7, or Vanchor cable 66 can beniade to be 'adjustableso that the 'radiusgo'f-the load side'of the jib derrick can be readily altered. Usually, only one radius is needed for each column in-` stallation in order that each new section of column C hangs directly over the section previously placed. Y

Another modification which can Abe made involves Vthe coniiguration of the jib derrickY framework as shown in FIGURES 2 and 6. In this assembly the chord member 56 of the framework truss is replaced by dihedral strut rods -85 and S6.

Suitable rod connectors

87 and 88 are used'to connect the inner ends of the rods 85 and 86-to the spacer strut'r58 and base vbracket 53 and -the outer ends of the

rods

85 and 86 with

brace rods

59 and 60, as well as provide a sheave journal -at the load end and anchor end of the framework depending upon the selected ldesign. Any arrangement of structural members which will supportthe applied load is satisfactory. In Vstill another embodiment, a counterweight such as shown schematically in FIGURE 3 replaces the lower anchor system.

In operation, lifting hook 80 coupled with a suitable lifting device, such as conventional lifting clamps 90, is attached to the column piece to be lifted. The load falls, although shown as a single fall, can be multiple parts to form a load block having a'substantial mechanical advantage. While the lift is being made, tag lines are used to swing the new column section into place. As the load portion of the jib mast extension is being swung into place, the anchor portion being so mounted also rotates horizontally through the same arc. Therefore, the load on the jib mast section of the Yderrick isV always vertical.

The jumping operation of the erection derrck employing the instant invention which is the subject of U.S. Patent 2,754,012 is carried out as follows:

With the mast support 11 and 34 secured to thecolum'n fC by the mast support attachment means described above, the jib derrick 56 can be employed to lift a second column section. The initial column installation is generally made using a truck-mounted crane or the like. The derrick can then be rotated on the mast 12 to swing the second section into position over the installed column section C in which position it may be secured thereto. When it becomes necessary to"jump the mast, the cable of the mast extension ssecured to the fitting 91 attached to themast supportV 34 and the fastening devices which secure the" mastvsl'lpport tothe column C are removed.

The upper mast support 34 is then lifted upwardly by means of the jib derrick to the new position where it is secured to the upper portion of the column section by attachment means previously -provided on the upper part of the new column extension. The rnast may be then secured to thefupper mast support 34 -by means of the pin and

aperture device

45 and 46 previously described. The cable on the derrick is Vthen released from the fitting 91 and secured to a fitting 92 attached to the member 11.`

Bolt 14 is'then withdrawn and the various pins which secure the member 11 to the column C are removed and the jib derrick 56 employed to lift the mast'support 11 to the new position wherein it is secured to the attachment means previously attached to the top of the new column sections. By removing the pin-45 whichsecures the lmast to the upper mast support 3,4 and by` pulling on the cable 31, the mast is then slid upwardly through the mast supports11and34 until it reaches theiposition relative thereto which it had previously occupied, whereupon the, bolt 14 and the pin 45 are -reinserted and the mast and `derrick are then ready for use to hoist another column section into position, Succeeding column sections may be elevated in vposition by moving lthe Ysupportspmast and derrick upwardly as just described. It is apparent, therefore, that other mast structures and jumperlfgniast support systems can be used in conjunction with the jib derri'ckgf this invention. l i, Y

The jib derrick can-be constructed from conventinal materials-of construction. In selecting the derrick design, a truss framework should be employed which will provide a -load armhaving substantially thesame extentl as the anchor arm; however, variations in length can be used Ifor different erection problems such as large diameter column installations. In the event thatMthe-jib yderrick 56 is arranged such that the load arm has a different radius than the anchor arm, provisions must be made, as shown in 'FIGURE 2,1for arranging the load falls so as to permit the jib derrick to exert/a force on the mast structure substantially coaxial with the longitudinalaxis Yof the mast. It will be noted that the jib derrick 576 shown,v in FIGURE 2 has `been pivoted in a vertical plane so that the load arm and anchor arm do not have the same'eitf tent. VIn, the jibderrick arrangement shown in FIGURE 2, hook is secured to a sheave block 95. The loadfall 81 is reeved through the sheave block `95 and itsvterminal end secured to lug 96 of the sheave journal at the load end of the framework. By securing the load fall -81 in this manner, a proper balancing of the forces canobtainY to effect theobjectives ofY this invevntion which provides a jib derrick which will eliminate stresses due to bending in the mast structure of a construction facility.

While We have shown and described certain embodiments of our invention, it is to be understood that it is capable of many modifications. Changes, therefore, in the method, construction and arrangement may be made without departing from the spirit and scope of the invention as disclosed in the appended claims.

What isclaimed is:

1. In a masted apparatus for facilitating the erection of an elevated column, a mast-mounted jib derrick comprising a unitary truss framework having a load portion and an anchor portionoppositely extending `from an intermediate mounting pivot, said mounting pivot adapted to permit the rotation of said truss framework in asubstantially horizontal plane, a rotatable sheave journalled in the free end of said load portion, a direction-,changing sheave mounted on said framework adjacent ysaid anchor portion, and means vertically depending from the terminal end of said anchor portion for anchoring said anchor portion to resist the upward displacement thereof.

`2. In a masted apparatus for facilitating the erection Vof an elevated column, a mast-mounted'jib derrick comprising a unitary truss framework having a load portion andv an anchor portion oppositely extending Yfrom an intermediate mounting pivot, said mounting pivot adapted to permit the rotation of said truss framework in a substantially horizontal plane and including a yoke portion to which said framework is pivotally attached to permit the angular displacement thereof in a vertical plane, a rotatable sheave journalled in the free end, a directionchanging sheave mounted on said framework adjacent said anchor portion, and means vertically depending from the terminal end of said anchor portion for anchoring said anchor portion to resist the upward displacement thereof.

3. In a masted apparatus for facilitating the erection of an elevated column, a mast-mounted jib derrick comprising a unitary truss framework having a load portion and an anchor portion oppositely extending from an in termediate mounting pivot, said mounting pivot adapted to permit the rotation of said truss framework in a substantially horizontal plane and including a yoke portion to which said framework is pivotally attached to permit the angular displacement thereof in a vertical plane, a rotatable sheave journalled in the free end, a directionchanging sheave mounted on said framework adjacent said anchor portion, and means vertically depending from the terminal end of said anchor portion for anchoring said anchor portion to resist the upward displacement thereof including a downwardly extending jib stay.

4. In a masted apparatus for facilitating the erection of an elevated column, a mast-mounted jib derrick comprising a unitary truss framework having a load portion and an anchor portion oppositely extending from an intermediate mounting pivot, said mounting pivot adapted to permit the rotation of said truss framework in a substantially horizontal plane and including a yoke portion to which said framework is pivotally attached to permit the angular displacement thereof in a vertical plane, a rotatable sheave journalled in the free end, a directionchanging sheave mounted on said framework adjacent said anchor portion, and means vertically depending from the terminal end of said anchor portion for anchoring said anchor portion to resist the upward displacement thereof including a downwardly extending jib stay adapted to be rotatably attached to said masted apparatus and substantially remain in the vertical plane of said jib derrick.

5. In a masted apparatus in accordance with claim 4 in which said jib stay is adjustable.

6. In a masted apparatus for facilitating the erection of an elevated column, a mast-mounted jib derrick comprising a unitary truss framework having a load portion and an anchor portion oppositely extending from an intermediate mounting pivot, said framework comprising a parallelogram truss having a dihedral strut assembly and an opposed dihedral brace assembly, said mounting pivot adapted to permit the rotation of said truss framework in a substantially horizontal plane and including a yoke portion to which said framework is pivotally attached to permit the angular rotation thereof in a Vertical plane, a rotatable sheave journalled in the free end, a directionchanging sheave mounted on said framework adjacent said anchor portion, and means vertically depending from the terminal end of said anchor portion for anchoring said anchor portion to resist the upward displacement thereof including a downwardly depending jib stay adapted for attachment to said masted apparatus.

References Cited in the tile of this patent UNITED STATES PATENTS

Claims

1. IN A MASTED APPARATUS FOR FACILITATING THE ERECTION OF AN ELEVATED COLUMN, A MAST-MOUNTED JIB DERRICK COMPRISING A UNITARY TRUSS FRAMEWORK HAVING A LOAD PORTION AND AN ANCHOR PORTION OPPOSITELY EXTENDING FROM AN INTERMEDIATE MOUNTING PIVOT, SAID MOUNTING PIVOT ADAPTED TO PERMIT THE ROTATION OF SAID TRUSS FRAMEWORK IN A SUBSTANTIALLY HORIZONTAL PLANE, A ROTATABLE SHEAVE JOURNALLED