US3187838A - Scaffolding structure - Google Patents

Description

June 8, 1965 R. E. STEWART, JR.. ETAL 3,187,833

SCAFFOLDING STRUCTURE Filed Oct. 2, 1963 3 Sheets-Sheet 1 INVENTORS. 1905597 5. STEWARTJZQ. OIPLEAN B. RAP/ER ArmP/vEy June 1955 R. E. STEWART, JR., ETAL 3,187,838

SCAFFOLDING STRUCTURE Filed 001;. 2, 1963 3Sheets-Sheet a 29a 20 20 INVENTORS- ROBE/P7 E. STEWART JR.

OELEAN B. RAP/2 BY w QW ATTOPNEY United States Patent 3,187,838 SCAFFGLDING STRUCTURE 1 Robert E. Stewart, in, 8458 Periwinkle Drive, Euena Park, Calif, and Orleau B. Rapier, 8357 Golden, Paramount, Calif.

Filed Oct. 2, 1963, Ser. No. 313,223 10 Claims. (Cl. 182-144) The present invention relates generally to scaffolding,

and more particularly to a scaffold that is adapted to be removably mounted in an encircling position on building structures such as cylindrical vessels, fractionation towers, chimneys, and the like, and moved vertically relative thereto.

A major object of the present invention is to provide a scaffold that encircles a structure of the type described which is supported from the upper portion thereof I and can be moved relative thereto without the necessity of erection from the ground up, whereby the ground surface surrounding the structure is maintained in a clear condition and work can be carried out thereon without interference.

Another object of the invention is to provide a scaffold that includes a support forthe workmen, inside and/or outside the structure being Worked on, with the supports being adapted .to be moved concurrently upwardly or downwardly as desired.

A still further object of the invention is to provide a scaffold in which a numberv of rectangular sections are removably connected to define a multi-sided framework which surrounds a structure to be worked on and is maintained at a fixed distance relative thereto as the framework is moved upwardly or downwardly.

Yet another object of the invention is to provide a scaffold which is vertically movable relative to structures which are substantially greater in height than in width without recourse to grading a sloping, congested or unstable ground condition that may exist adjacent the base of the structure. I j j A further object of the invention is to provide a scaffold that can be easily and quickly erected as well as disassembled, can be transported from one job site to another, assembled and dismantled by relatively unskilled personnel, provides optimum safety in operation, and requires a minimum of maintenance attention.

Yet still another object of the present invention is to provide a scaffold that is assembled from a plurality of sections, at least a portion of which is adjustable as to width, with portions of these sections being adapted to be formed into a configuration that avoids outwardly projecting fixtures on the structure, such as piping, walk 1 ways, and the like.

These and other objects and advantages of the invention will become apparent from the following description of a first and an alternate form thereof, and from the accompanying drawings illustrating the same, in which:

FIGURE 1 is a top plan view of the first form of the scaffold mounted on the upper portion of a cylindrical structure;

FIGURE 2 is a vertical cross-sectional view of the scaffold shown in FIGURE 1, taken on line 2-2 thereof;

FIGURE 3 is a fragmentary vertical cross-sectional view of the scaffold shown in FIGURE 1, taken on line 3-3 thereof;

FIGURE 4 is a fragmentary'top plan View of two adjacent column plates removably interlocked to maintain two scaffold sections in a desired relationship;

FIGURE 5 is a side elevational view of one of th scaffold sections used with the first form of scaffold;

FIGURE 6 is a side elevational view of -a scaffold positioner; 7

ice

scaffold sections used with the alternate form of scaffold.

With continuing reference to the drawings for the general arrangement of the first form of scaffold, it will be seen in FIGURE 2 to be movably mounted on an openended cylindrical structure A. The structure A which could be any one of a variety of types such as a chimney, fractionation tower, vertical vessel, tank, or the like, is supported on a foundation B.

The first form of scaffold C, as may best be seen in FIGURES 2 and 5, includes a base D formed from I- beams 10 arranged in the shape of a Greek cross. The outer end portions of beams 10 rest on the upper circumferential edge 12 of structure A. Base D supports an upwardly extending shell E, from the upper portion of which four arms F project. Shell E is temporarily attached to the top of closed end structures in lieu of base D. Arms F are in equal spaced relationship, and may be rotated within shell E relative to the beams 19 so that they do not lie in the same vertical plane therewith.

A number of sections G are provided, one of which is shown in detail in FIGURE 5. Eight sections G are joined in the manner shown in FIGURES 1 and 2 which completelyencircle the structure A. Square and rectangular shapes can also be assembled using four sections G.

Sections G are each fabricated from a number of components which are removably held together, whereby each section is variable as to the width thereof. Each section G is rectangular, and comprises two laterally spaced vertical columns 14 which support vertically spacedhorizontally disposed connecting plates H that can overlap, as shown in FIGURE 4. Bolts J engage vertically aligned bores 16 formed in the plates H, whereby the sections G may be removably held together to define the octagon shaped scaffold shown in FIGURES 1 and 2.

Four scaffold positioners K, the details of which are best seen in FIGURES 6 and 7, are supported from the lower end portions of alternately spaced pairs of columns 14 (FIGURES 1 and 2); The positioners K serve to maintain the sections G in fixed, radially spaced relationship relative to the exterior surface of the structure A as the sections are moved upwardly and downwardly relative thereto by means which will hereinafter be explained in detail.

Each of the columns 14 has three vertically spaced, horizontal platform level indicators L projecting therefrom,

each of which terminates in a circular flange 18. Columns 14 also have three horizontal, tubular reinforcing members M projecting therefrom which are in vertical alignment with indicators L and spaced a fixed vertical distance therefrom, as may best be seen in FIGURE 5. Each of the platform indicators L is above one of the plates H, and one of the reinforcing members M is positioned a short distance below the plate. The reinforcing members M terminate in a flange 20 that is in vertical alignment with the flange 18. Flanges 18 and 20 are connected by bolts or other conventional fastening means to complementary flanges 13a and 20:: that form a part of a spool piece N, as may best be seen in FIGURE 5.

An elongate rigid tube 22 extends downwardly from eachreinforcing member M, and the lower end of this tube is welded at 24 to one of the columns 14. A number of horizontal, vertically spaced rigid members 26 are thereof and rigidly affixed to the tube.

welded or otherwise afiixed to each column 14.- and tube 22 (FIGURE 6) for reinforcing purposes. A number of plank supports are utilized with the first form of scaffold which are shown in detail in FIGURE 9, and also in FIGURES'l and'2.

Each support 0 comprises a vertical length of channel iron 28 from which a second length of channel iron 3st projects in a direction normal relative thereto, with the second length being disposed'downwardly from the upper end of the'first length a substantial distance. A third length of channel iron 32 extends between the second and first lengths 28 and 30 respectively, in the manner shown in FIGURE 9 to reinforce the second length against a downwardly exerted load.

The first length 28 (FIGURE 9) includes first half portions 34 of pipe clamps. Second halfportions 36 of pipe clamps are provided which are connected by bolts 38 to the first half portions 34. When the bolts 38 are tightened, the clamp portions 34 and as are moved towards one another to permit the pipe portions to frictionally grip one of the columns 14 to hold the plank support 0 of whichthey form a part at a fixed elevation on scaffold section G.

The upper portions of plank supports 0 are adapted to engage the column 14 above the platform indicators L, with the upper surface 40 of the second channel length Elli-being substantially flush with the upper surface of the indicator. By useof the plank supports 0, planks F can be laid thereacross to define platforms at three different levels, as may best be seen in FIGURES 1, 2 and 5, to support workmen (not shown) who may be doing maintenance, painting, or other work on the exterior sur face of the structure A.

' -An upwardly extending lift plate 42 in which a number of spaced bolt holes 44 are formed is aflixed to the upper end of each column 14 in each section G, preferably as shown in FIGURES 4 and 5. The lift plates 42 of two adjacent scaffold sections G lie in the same vertical plane, and are connected .by a tie plate 46 (FIGURE 4). The tie plate 46 is connected to lift plates 42 by bolts 48 which extend through openings (not shown) in the tie plate and through'openings 44 in the lift plates to rigidly 96 to extend partially into the confines of tube 86.

The inner ends of the arms F are rigidly afiixed to tube 86 by bolting or the like, and these load arms rest on a spacer plate 98, which in turn is supported by end plate '74. A second spacer plate 1% is positioned above the arms F and is in abutting contact with a third plate m2, which is welded by beads 1% to tube 86. A number of gussets 1% extend outwardly from the tube 86, with the lower ends thereof in abutting contact with the third plate 1%.

A four groove sheave 11% is rotatably supported inside the shell E on a shaft llltl. Shaft 11!) is rigidly supported inside shell E by conventional means. An opening 112 is formed in shell E, and atube 114 extends therethrough, which is welded by beads "116 to the exterior surface of the shell, as best seen in FIGURE 3. V A flange II? is formed on the outer end of tube 114 which mates with a companion flange 129 that has a second tube 124 extending therefrom. Flanges 118 and 129 are removably connected by bolts 122..

In FIGURE 2 it will'be seen that each of the second cables 54 extends upwardly and inwardly over one of the first sheaves do, then over the second sheave 7d, and downwardly therefrom through an opening (not shown) in one of the load arms F to one of the pulley blocks 58. Each cable 54 extends upwardly from one of the pulley blocks 58 to engage one of the third sheaves. after passing through an opening (not shown) in arm F on which the third sheave is mounted. After passing one of the third sheaves '72, each cable 54 extends upwardly to engage one of the fourth sheaves :96, and then downwardly through the tube 86 to engage one of the grooves in the four groove sheave 168. After engaging the sheave 1%,

hold the two adjacent lift plates together. Each tie plate I 46 has an opening formed in the upper portion thereof through which a looped end 50 of a cable 52 is connected by a shackle bolt. The two looped ends 50 of each cable 52 are affixed to adjacently disposed tie plates 46, as shown in FIGURE 1, with the cable being connected at its center to a second cable 54.

I Aplatform Q is provided which is of suchsize as to.

be vertically movable within the interior of structure A.

Four third cables 56 extend upwardly from platform Q,

each of which has a pulley block 58 affixed to the upper end thereof.

Four single groovefirst sheaves 60 are rotatably sup- .ported on shafts 62 from bifurcated ends 64 of load arms F, and two parallel, laterally spaced, longitudinally extending plates 66 project upwardly from each arm, as may best be seen in FIGURES land 2. Two shafts extend between 'each pair of plates 66 and rotatably support second and third single groove sheaves 7i and '72, re-

spectively.

An-1 pperend plate 74 is welded by beads '76 to the shell E (FIGURE 3). A second plate 78 disposed below plate 74 inside shell E is welded to the shell by beads 8th..

Vertically aligned bores 82 and 84 are formed in plates 74 and 78. A heavy tube 86 extends upwardly through bores 82 and 84 and 'is welded to plate 78 'by' beads 83. Four slots 90 are formed in tube 86, in each of which a pair of lugs 92 is disposed on opposite longitudinal sides Each pair of lugs 92 supports a shaft 94 therebetween on which a fourth single groove sheave d is mounted.

Slots are sufficiently wide and long as to permit sheaves each cable 54 passes outwardly through the cable tubes I14 and 124 to another four groove sheave (not shown) which directs the cables in a vertical direction to engage conventional power-driven drum means (not shown) whereby the cablesmay be drawn upwardly relative to the structure A, or by the weight of the load on the cables, and release of the brake on the power-driven drum, permit it'to move downwardly relative to the structure.

The detailed structure of the positioners K is shown in FIGURE 6, which include an upper pipe clamp 126 from which a tube 1-28 extends outwardly. Tube 12% is with any one of the holes 132. When the bore in rod' 138 is so aligned, a pin (not shown) may be slipped through this bore to hold the rod in a'fixed, non-rotatable position relative to tube 128. Rod 138 supports a plate 140 on the end thereof, from which two parallel, laterally spaced side pieces 142 project. Side pieces 142 support a shaft 144 therebetween on which a wheel or roller 146 is-rotatably supported. When the rod 138 is positioned in the desired longitudinal relationship with tube 128, the wheel 146 is disposed adjacent the exterior surface of the structure A or actually in contact therewith, with the' four wheels serving to maintain the first form of 'scaifold'C in a substantially fixed horizontal position relative to the structure.

Each of the scaffold positioners K is mounted on the lower end, portion of one of the oolumns 14, as best seen in FIGURES 1 and 2, and each of the columns 14 has a small plate 148 welded or otherwise affixed to the lower end thereof. Each. of the plates 14% connects to the. upper end of a conventional hold-down assembly 15%, the lower end of which is affixed to an anchor 152, or

' in the ground 154 surrounding the foundation B.

A second conventional cable hold-down assembly 156 is provided that has the upper end thereof connected to a lug 158 which projects downwardly from the central portion of platform Q. The lower end of assembly 156 is afiixed to a suitable object 160 that is either driven into or embedded in the foundation B. The hold-down assemblies 150 and 156 can be manually adjusted to tension the cables forming a part thereof, and when so tensioned, the cables cooperate with cables 52 and 54 to hold the scaffold C at a desired elevation relative to structure A.

The detailed structure of the spool piece N is best seen in FIGURE wherein it will be seen that the platform indicators L include heavy metallic tubes 162 having the flanges 13 mounted on the outer end thereof. An L- shaped member 164 is provided that has a vertical leg 166 and a horizontal leg 168. The lower edge of leg 166 is welded to the upper portion of the tube 162. A gusset plate 170 extends between the upper surface of tube 162 and the lower surface of leg 168, and is welded to the tube and leg by beads 172. A triangular web 174 extends between the lower outer portion of tube 162 and an inner portion of the column 14.

The spool piece N (FIGURE 10) includes a vertically extending plate 176, on the upper edge portion of which a tube 178 is Welded, with a second tube 180 being welded to the lower edge thereof. The two tubes 178 and 180 support flanges 18a and 20a respectively at the ends thereof, and these two flanges abut against flanges 18 and 20, as previously described and as shown in FIGURE 5.

Two openings 182 are formed in plates 176, and two openings 184 are formed in plates 174. Two bolts 181 extend through openings 182 to engage eyes (not shown) formed on the end of a threaded tie rod 186. A bolt 187 extends through the opening 184 formed in plate 174 to engage an eye (not shown) on a threaded tie rod 188 that extends to a turnbuckle 190. Turnbuckle 190 engages threads on the tie rods 186 and 188, and when the turnbuckle is rotated in an appropriate direction it tensions the tie rods to cross-reinforce the first form of scaffold C. An L-shaped member 192 extends upwardly from tube 178 that is of the same structure as member 164.

Operation of the first form of scalford C is relatively simple. The base D is mounted on the upper portion of the structure A as shown in FIGURE 2 and inadvertent displacement thereof is prevented by clips 194 which descend from the lower outer end portions of the base D. The clips 194 abut against the upper exterior surface of the structure A. The clips 194 can be bolted or otherwise removably affixed to the structure A during the time the first form of scaffold is being used. When the base D is thus disposed the arms thereof support the shell E in the manner shown in FIGURE 2.

The detailed structure of the elements associated with the shell E are shown in FIGURE 3. The sections G are disposed in upright positions to encircle the structure A, with the plates 148 of these sections resting on the ground surface 154. Bolts I are then caused to engage opening 16 in the column plates H to hold the sections G in an .angular relationship to define the octagonal frame shown in FIGURE 1.

The lift plates 42 are connected to tie plates 146 as previously described, with the tie plates in turn being connected to each two adjoining tie plates by an upwardly extending cable 52. Each cable 52 is connected to a second cable 54, which latter cable engages the first sheave I 60, second sheave 7t pulley block 58, third sheave 72,

fourth sheave 96, and the four groove she-ave 108 to extend through tubes 114 and 124 to power means for raising and lowering each of the cables 54. Cables 54 are con- 6 currently raised and lowered by power means (not shown).

The pulley blocks 58 are connected by cables 56 to platform Q, and as cable 54 is moved in a direction to raise the octagonal frame defined by the first form of scaf fold sections G, the platform is raised concurrently therewith. Planks R are laid across supports 0 (FIGURE 9) in positions illustrated in FIGURE 1 to define three platforms S-1, S-2 and 8-3 shown in FIGURE 2. By manipulation of cables 54, the assembled scaffold sections G may be raised or lowered to a desired elevation relative to the structure A, whereby workmen thereafter supported on the platforms S1, S-2 or S3 have access to the exterior surface of the structure A to perform necessary work thereon.

When the sections G are assembled as an octagonal framework (FIGURES 1 and 2) and have been raised to a desired elevation relative to the structure A, the tie downs and 156 are adjusted to maintain tension thereon to minimize movement of the assembled sections relative to the structure. Transverse movement of the assembled sec-tions G relative to the structure A is prevented by the scaffold positions K which are in contact with the exterior surface of the structure. As the first form of sections G are moved relative to the structure A, the platform Q is likewise moved, from which Work can be performed on the interior of the structure while work is progressing on the exterior thereof. It will be particularly noted that when the first form of scaffold sections G are used as described, the area thereunder is substantially free of obstructions whereby work can be carried out thereon by men not supported on the scaffold.

Should the structure A have a nozzle 196 with a pipe 198 connected thereto (FIGURE 1) that would interfere with upward and downward movement of the first form of scaffold C, one of the sections G can be removed from the assembly, as shown in FIGURE 1. The sections G on each side of the nozzle 1% and pipe .198 are connected by horizontal and vertically diagonal tubes 197. Tubes 197 are removably connected to columns 14 by pipe clamps (not shown). These horizontal and diagonally disposed tubes 197 are alternately removed and replaced on the columns 14 as the assembly shown in FIGURE 1 is moved upwardly and downwardly relative to the structure A.

A second form of scaffold section U is shown in FIG- URE 11 which is similar to the first form G. However, scaffold section U is not adjustable as to width. Section U is used in the same manner as the first form thereof and serves the same purpose.

Each scaffold section U includes two laterally spaced, parallel columns 21% that have lift plates 212 on the upper ends thereof and plates 214 on the lower ends of the columns. Circular plates 213 are mounted on columns 210 that are structurally identical to plates H. Columns 21%) are connected by cross pieces 216, the ends of which are Welded or otherwise permanently connected to the columns. The cross pieces 216 are reinforced by reinforcing means 213, which are preferably tubular. Platform indi caters 22d extend between the columns 219 and serve the same function as indicators 164 in the first form of section.

The use of the second form of scaffold section U is the same as the first form thereof, and accordingly its mode of operation need not be repeated.

Although the present invention is fully capable of achieving the objects and providing the advantages hereinbefore mentioned, it is to be understood that it is merely illustrative of the presently preferred embodiments thereof and we do not mean to be limited to the details of construction herein shown and described, other than as de fined in the appended claims.

We claim:

1. A platform supporting scaffold adapted to substantially encircle a structure of greater height than Width and be moved vertically relative thereto, including:

(a) a plurality of generally rectangular rigid sections,

each of which comprises two parallel, laterally spaced columns, and reinforcing means extending therebetween;

(b) a plurality of horizontal plates extending outwardly from said columns and being of suificient size that said plates on said columns which are most adjacent to "one another have plate portions that overlap one another, with said overlapping plate portions having a plurality of spaced openings form-ed therein, at least a part of which openings are alignable with one another; and

(c) a plurality of elongate rigid members that removably engage said openings which are aligned with one another for holding said sections together;

((1) second means for holding said sections in said multi-sided frame at substantially fixed radial distances relative to said structure;

(e) third means for defining at least one horizontal platform;

(f) fourth means for removably supporting said third means from said sections; and

(g) fifth means for concurrently raising and lowering said sections when defining said multi-sided frame relative to said structure to permit performance of Work on the exterior surface thereof by personnel supported on said third means.

2. A scaffold as defined in claim 1 wherein at least a portion of said reinforcing means in said sections is adjustable to provide sections of sutficient width as to encircle said structure when said sections define said multi-sided frame.

3. A scaffold as defined in claim 1 wherein at least a portion of said reinforcing means in said sections is adjustable, with each of said reinforcing means that is adjustable including:

(a) a plurality of vertically spaced, horizontal, tu-

bular members that are in longitudinal alignment and extend inwardly toward one another from said columns;

(b) a plurality of flanges mounted on the inner ends of said tubular members;

(c) a spool piece of desired width comprising a plurality of horizontal, vertically spaced tubes that are horizontally alignable with at least a portion of said tubular members, and a plurality of companion flanges mounted on the ends of said tubes which can be placed in abutting contact with said flanges on said tubular members; and

(d) means for removably connecting said flanges on said tubular members to one another to provide a scaffold section of a first width and said flanges on said tubular members to said companion flanges on said tubes to provide a scaffold section of a second width.

4. A scafl'old as defined in claim 1 wherein said secmeans comprises a plurality of planks, which when laid side-by-side define said platform, and includes:

(a) two vertically disposable first lengths of a rigid material; (b) .a plurality of pipe clamps that removably sup port said first lengths from two of said columns which are adjacently disposed; and

(c) two second lengths of rigid material that extend inwardly towards said structure from said first lengths, which second lengths removably support said planks thereon to define said platform.

6. A scaffold as defined in claim 1 wherein said fifth means includes:

(a) a vertically extending hollow shell;

(b) a base for supporting said shell on the upper portion of said structure;

(0) a multi-groove sheave rotatably supported in said shell;

((1) a plurality of single groove sheaves rotatably supported from said shell;

(e) a cable tube in communication with an opening in said shell;

(f) a plurality of cables extending through said tube to engage said multi-groove sheave and extend upwardly therefrom to engage said single groove sheaves and then extend downwardly towards said sections; and

(g) means for connecting the lower ends of said cables to the upper portions of said sections, with said sections being raised and lowered as said cable is moved outwardly and inwardly relative to said cable tube.

7. A scaffold as defined in claim 1 wherein said fifth means includes:

(a) a vertically extending hollow shell;

(b) a base for supporting said shell on the upper portion of said structure;

(c) a plurality of power driven drums supported from said shell;

(d) a plurality of cables wound on said drums; and

(e) means for connecting the lower ends of said cables to the upper portions of said sections, with said sections being raised or lowered as said drums are rotated.

8. A scaffold as defined in claim 1 wherein said fifth means includes:

(a) a plurality of lifting plates affixed to the upper ends of said columns;

(b) a plurality of tie plates extending between each two adjacently disposed lifting plates;

(0) means for removably afiixing said tie plates to said two lifting plates;

(d) a plurality of first cables, the ends of each of which are connected to two adjacently disposed tie plates; 7

(e) a plurality of second cables, the lower end of each of which is connected to a center portion of one of said first cables;

(f) a base in the form of a horizontally rigid cross that is supported on the upper extremity of said structure;

(g) means for removably holding said cross on said structure;

(h) a hollow shell extending upwardly from said cross; a

(i) a multi-groove sheave rotatably, supported in said shell;

(1') a cable tube extending outwardly from said shell and in communication with an opening formed therein; 7

(k) a platform horizontally disposed inside said structure and of such cross: section as to be vertically movable therein;

(l) a plurality of third cables extending upwardly from said platform; 7

(m) a plurality of pulley blocks mounted on the upper ends of said third cables that are aflixed to said platform;

(n) a plurality of horizontal arms extending outwardly from said shell;

(0) a plurality of first sheaves rotatably supported on said arms;

(p) a plurality of pairs of second and third sheaves, with each of said pairs being disposed above one of said arms;

(q) means for rotatably supporting each of said pairs of second and third sheaves above each of said arms;

(r) a plurality of fourth single groove sheaves disposed in the upper portion of said shell; and

(s) means for rotatably supporting said fourth sheaves from said shell, with each of said second cables extending upwardly to engage one of said first and second sheaves, then downwardly to engage one of said pulley blocks, then upwardly to engage one of said third and fourth sheaves, then downwardly to engage one of said grooves in said multi-groove sheave, and then outwardly through saidcable tube, with said plurality of cables when concurrently moved inwardly or outwardly through said cable tube concurrently raising and lowering said sections on the exterior of said structure and said platform situated within the confines thereof.

9. A multi-platform supporting scaffold for encircling a structure of substantial height and adapted to be moved vertically relative thereto, including:

(a) a plurality of rigid rectangular sections, each of which includes two parallel, laterally spaced vertical columns;

(b) a plurality of vertically spaced, horizontal, tu-

bular members that are in longitudinal alignment and extend inwardly toward one another from said columns;

(c) a plurality of flanges mounted on the inner ends of said tubular members;

(d) spool pieces of desired width comprising a plurality of horizontal, vertically spaced tubes that are horizontally alignable with at least a portion of said tubular members, and a plurality of companion flanges mounted on the ends of said tubes which can be placed in abutting contact with said flanges on said tubular members to attain a plurality of available horizontal widths of said sections;

(e) means for removably connecting said flanges on said tubular members to said companion flanges on said tubes to provide scatfold sections of various widths, with each of said widths being dependent upon the lengths of said spool pieces;

(f) variable length reinforcing means for maintaining each of said sections in a rectangular configuration of desired width;

(g) first means for removably attaching a plurality of said sections together to define a multi-sided frame which encircles said structure at a substantially fixed radial distance therefrom;

(h) a plurality of platforms supported from said sections; and

(i) second means for concurrently raising and lowering said sections when defining said multi-sided frame relative to said structure to permit performance of work on the exterior surface thereof by personnel supported on said platforms.

10. A scaffold as defined in claim 9 wherein said second means includes:

(a) a vertically extending hollow tube;

(b) means for supporting said tube on the upper portion of said structure;

(0) a plurality of vertically disposed sheaves circumferentially spaced about said tube and positioned in alignment with vertically extending slots formed in said tube;

(d) means for rotatably supporting said sheaves from said tube;

(e) a plurality of rigid arms that extend outwardly from said tube and are in substantially the same vertical planes as said sheaves;

(f) a plurality of sets of first, second and third sheaves rotatably supported on said arms;

(g) a plurality of pulley blocks afiixed to the interior surface of said structure; and

(h) a plurality of cables that extend upwardly through said tube to engage said sheaves rotatably supported thereon, which cables then extend downwardly over said third sheaves to engage said pulley blocks and thereafter pass upwardly over said second and first sheaves to again extend downwardly to a point where the lower ends thereof are afiixed to said sections, with the portions of said cables in said tube when moved downwardly relative thereto raising said sections, and with said portions of said cables in said tube when moved upwardly relative thereto lowering said sections.

References Cited by the Examiner UNITED STATES PATENTS Re. 20,653 2/38 Lamb 182--l87 2,164,519 7/39 Hayner 182-145 2,340,487 2/44 Paguette 182-82 2,9 16,102 12/59 Reinhardt l82143 2,957,582 10/ Lusk 182-144 FOREIGN PATENTS 26,109 12/01 Great Britain. 929,545 6/63 Great Britain.

HARRISON R. MOSELEY, Primary Examiner.

REINALDO P. MACHADO, Examiner.

Claims (1)

1. A PLATFORM SUPPORTING SCAFFOLD ADAPTED TO SUBSTANTIALLY ENCIRCLE A STRUCTURE OF GREATER HEIGHT THAN WIDTH AND BE MOVED VERTICALLY RELATIVE THERETO, INCLUDING: (A) A PLURALITY OF GENERALLY RECTANGULAR RIGID SECTIONS, EACH OF WHICH COMPRISES TWO PARALLEL, LATERALLY SPACED COLUMNS, AND REINFORCING MEANS EXTENDING THEREBETWEEN; (B) A PLURALITY OF HORIZONTAL PLATES EXTENDING OUTWARDLY FROM SAID COLUMNS AND BEING OF SUFFICIENT SIZE THAT SAID PLATES ON SAID COLUMNS WHICH ARE MOST ADJACENT TO ONE ANOTHER HAVE PLATE PORTIONS THAT OVERLAP ONE ANOTHER, WITH SAID OVERLAPPING PLATE PORTIONS HAVING A PLURALITY OF SPACED OPENINGS FORMED THEREIN, AT LEAST A PART OF WHICH OPENINGS ARE ALIGNABLE WITH ONE ANOTHER; AND (C) A PLURALITY OF ELONGATE RIGID MEMBERS THAT REMOVABLY ENGAGE SAID OPENINGS WHICH ARE ALIGNED WITH ONE ANOTHER FOR HOLDING SAID SECTIONS TOGETHER; (D) SECOND MEANS FOR HOLDING SAID SECTIONS IN SAID MULTI-SIDED FRAME AT SUBSTANTIALLY FIXED RADIAL DISTANCES RELATIVE TO SAID STRUCTURE; (E) THIRD MEANS FOR DEFINING AT LEAST ONE HORIZONTAL PLATFORM; (F) FOURTH MEANS FOR REMOVABLY SUPPORTING SAID THIRD MEANS FROM SAID SECTIONS; AND (G) FIFTH MEANS FOR CONCURRENTLY RAISING AND LOWERING SAID SECTIONS WHEN DEFINING SAID MULTI-SIDED FRAME RELATIVE TO SAID STRUCTURE TO PERMIT PERFORMANCE OF WORK ON THE EXTERIOR SURFACE THEREOF BY PERSONNEL SUPPORTED ON SAID THIRD MEANS.

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