US3378101A - Scaffold - Google Patents

Description

April 1968 F. D. ZEITLER 3,378,101

SCAFFOLD Filed Aug. 12, 1966 3 Sheets-Sheet 1 Fig.

I Frank/m 0. Ze/fler INVENTOR. 34 70 50 April 16, 1968 F. D. ZEITLER 3,378,101

SCAFFOLD Filed Aug. 12, 1966 3 Sheets-Sheet 2 q; & Frank/m D; Ze/f/er INVENTOR.

E Q w k N BY M406 N Q Attorneys & Q

United States Patent 3,378,101 SCAFFOLD Franklin D. Zeitier, 208 W. Liberty St, Punxsntawney, Pa. 15767 Filed Aug. 12, 1966, Ser. No. 572,625 15 Claims. (6!. 18216) The present invention generally appertains to scaffolds and similar lifting devices, which are adapted to support workmen at various working heights in relationship to a vertical structure, and more particularly relates to novel improvements in a mobile, vertically adjustable scaffold construction.

The provision of mobile scaffolds which are wheel mounted for transportation from place to place and which have upright supporting means on a wheel carrying base, with platform supporting means mounted on the vertical supporting means for positioning thereby at various heights are known. Such known constructions employ hoisting means for the platform supporting means, so as to raise and lower the platform, the hoisting means generally being composed of a rotatable drum journaled on the base and having cables which are extended over the upper ends of the vertical supporting means and attached to the platform supporting means on the vertical supporting means.

The principal drawbacks, with such known constructions, are that they are extremely expensive to manufacture and, therefore, very expensive to purchase and that the mobile base is not maneuverable enough for easy placement in relation to the work, such as a vertical wall structure, and that the hoisting means is extremely complicated, cumbersome and also disposed so that it can be subject to accidental breakage or malfunctioning and can interfere with the movements of the workmen on the platform and interfere with the hoisting of working materials to the workmen, when they are on the platform, and the platform is raised above the vertical supporting means. In addition, the hoisting means is so structurally related between the base mounted drum or winch operating means therefor and the platform supporting means on the vertical supports that the upward, maximum height of the supporting means is unnecessari- 1y limited and restricted.

Accordingly, an important object of the present invention is to provide a scaffold which overcomes the foregoing drawbacks, attendant with known, similar types of scaffolds or lifting devices and to provide an inexpensive, extremely compact and maneuverable scaffold.

Another important object of the present invention is to provide a scaffold which is movable in an erected condition or state in an extremely simple and most efficient manner for maximum maneuverability, and which is of a collapsible nature, whereby it may be easily transported, in a collapsed and compact arrangement, from one work site to another.

Another important object of the present invention is to provide a scaffold which includes a very simple, effective and easily and safely actuated and controlled hoisting arrangement for raising and lowering a platform to selected heights, .the hoisting arrangement being formed and disposed so that it is protected from damage and so that the workmen are protected and so that it does not present any structural interference with the movements of the workmen on the platform or with the handing of materials to the workmen on the platform.

These together with other objects and advantages which will become subsequently apparent reside in the 3,378,191 Patented Apr. 16, 1968 details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE 1 is an end eleva-tional view of a scaffold, constructed in accordance with the present invention, and showing the platform in a lowermost position;

FIGURE 2 is a side elevational View of the scaffold, showing the platform in a raised position;

FIGURE 3 is a fragmentary end elevational view showing the platform disposed above the upper end of the vertical supports therefor;

FIGURE 4 is a detailed, fragmentary perspective view, showing the structural details of the hoisting arrangement in relation to the vertical supports and platform supporting means and showing the structural details of the platform assembly;

FIGURE 5 is a fragmentary, longitudinal horiozntal sectional view, taken substantially on line 55 of FIG- UKE 2;

FIGURE 6 is a transverse, vertical cross-sectional view, taken substantially on line 6-6 of FIGURE 5;

FIGURE 7 is a transverse sectional view, taken on line 77 of FIGURE 2 and illustrating a safety lock arrangement, and,

FIGURE 8 is a top plan view showing the scaffold in a collapsed or folded condition resting on the mobile base frame for transportation from one working site to another working site.

Referring now more particularly to the accompanying drawings, the scaffold, generally designated by the reference numeral fl), comprises an elongated base frame 12, which is of open rectangular form. The base frame 12 includes opposing side frame bars 14 and 16, which are joined at their opposing ends by transversely disposed end bars 18 and 28. The frame bars are of noncircular cross-sectional shape for rigidification purposes.

The base frame 12 is further com-posed of transverse brace bars 22 and 24, which extend between and are suitably secured, as by welding or the like, to the side frame bars 1'4 and 15. The brace bar 22 is disposed parallel with and spaced inwardly from the end frame bar 2% and defines therewith one end section of the base frame, while the brace bar 24 is disposed parallel with and spaced inwardly from the end bar 1e and defines therewith an opposing end section of the base frame. The brace bars 22 and 24 support diagonally disposed, upwardly and longitudinally extending brace rods 26 and 28 which are attached at their inner converging ends to a longitudinally extending brace rod 39, which is suitably secured at its ends to the crossbars 22 and 24 and is disposed centrally of the base frame.

Each of the end sections is provided with steerable, ground engaging wheel assemblies 32 and 34, which movably support the base frame 12. Each of the wheel assemblies has a draft connection means 36, so that the frame can be drafted or towed by a draft vehicle from either end, thereby rendering it more maneuverable for placing the frame easily and quickly in position relative to a vertical work structure, and making it more mobile for drafting purposes when the frame is being transported by the draft vehicle from one work site to another work site.

Each of the wheel assemblies and its associated draft or towing connection 36 are identically constructed and, therefore, a detailed description of the steerable wheel assembly 3 2-, as shown more particularly in FIGURES 3 l, 5 and 6, will suffice for an understanding of the wheel assemblies and the associated draft connection 36.

The wheel assembly 34 comprises ground engaging wheels 38 and 4%, which are rotatably mounted on stub axles 42 carried by the outer ends of an axle 44. The axle 44 is supported by depending standards 46 and 48, which are welded to the outer ends thereof and secured, as by welding, to the underside of the crossbar 24, adjacent its ends. The diagonal brace rods 26 and 28 extend upwardly from the standards 46 and 4% and are attached to the longitudinal brace rod 39, between the cross braces 22 and 24. The stub axles 42 are mounted by conventional kingpin assemblies 55 to the outer ends 44 of the axle which is fixed at its raised center portion 52. to a crossbar 54, which extends between the standards 46 and 48, as shown in FIGURES 1 and 6.

A tie rod 56 is pivotally attached at its opposing clevis ends 58 to projecting tongues or arms as on the stub axles 4'2. and the central portion of the tie rod 56 is pivotally attached, as at at, to an arm 64, which projects rearwardly from a vertical collar 65. The collar 56 is rotatably mounted by a bracket means d8 on the underside of the center portion 56 of the axle and is provided with a forwardly projecting tongue arrangement 69. A tow bar 70 is pivotally secured by a pivot assembly 72 at its rearward end to the tongue 69 for movement about a horizontal axis. The tow bar 74) is provided on its outer end with conventional hitch means 74, whereby it can be readily and easily attached to the hitch on a draft vehicle. Thus, by virtue of the tow or draft bar 79, the base frame is drafted in a steerable manner.

As afore-stated, the wheel assemblies 32 and 34 are of identical construction and operation, so that the base frame 12 can be drafted from either end and, when it is drafted from one end, then means is provided for disposing the non-used tow bar in an inoperative position and for rendering the associated ground-engaging wheels non-steerable, so that such wheels merely constitute tracking rear wheels.

iAs shown in FIGURE 2, such means comprises a pair of cars 76, which extend downwardly and outwardly from each of the end bars 18 and 2t and between which the associated draft bar 70 is adapted to be disposed in the raised position, as shown in dotted lines in FIGURE 2. The draft bar is held captive between the cars by a retaining pin 78. Thus, the captive draft bar 70 is not only held in an inoperative position and is held out of ground-engagement but also serves to lock the wheels of the associated wheel assembly against steering movements.

'A scaffold construction 8% is carried by the base frame 12 and comprises a pair of elongated tubular supports 82 and 84. Each of the supports is of circular cross-section and is hollow and has open lower and upper ends 86 and 88, respectively.

Each of the crossbars 22 and 24 is provided with a pair of upstanding apertured ears 9'0 and $2, the ears being slightly offset, lengthwise of the base frame, as can be appreciated from a consideration of FIGURE 8. The lower end portions 86a of each of the supports 82 and 84 are provided with radial apertures, alignable with the apertures in the ears to receive pivot pins 94, whereby the supports 82 and 84 are pivoted to the brace bars 22 and 24 for vertical swinging movement about axes, transverse of the longitudinal axis of the base frame. The supports 82 and 84 are adapted to be disposed in rigid upright positions and positioned substantially in alignment longitudinally of the base frame, as shown in FIG- URES 1 and 2. The supports are held in such upstanding, rigid and related vertical positions by brace rods. Thus, innermost brace rods 95 and 93 have their lower ends secured by pins 100 to upstanding ears 182 and 104 on the side frame bar 14-, the ears being disposed substantially centrally of the frame bar. The brace rods 96 and 93 are in crossed relationship and have their upper ends secured by pins 106 to the supports 812 and 8d. Complemental brace rods 168 and 1-10 have their lower apertured ends secured by pins 112 to upstanding apertured ears 114 provided on the upper face of the side frame bar 14, adjacent the crossbars 22 and 24. The upper apertured ends of the end brace rods 168 and 116 are fixed by the pins 1% to the supports.

As can be appreciated from a consideration of FIG- URE 2, the inner brace rods 96 and 98 and the outer brace rods 16% and 110 serve to retain the supports in secure and rigid upright positions. The pins 100, 166 and 112 are removable, so that the supports can be disposed in generally horizontally collapsed positions res ing on the end sections of the base frame, as shown in FIGURE 8.

When the supports are erected, they are held in their secure, upright positions by the brace rods, which are attached to the ears on the side frame bar 14 and to the supports by the removable pins.

Supportin members 116 and 118 constitute part of the scaffold construction and are slidably sleeved on the supports and constitute the means for supporting the platform assembly 121 and for raising and lowering the same through a hoisting means, as will be described. The support members 116 and 113 are in the nature of sleeves, which are slidably disposed on the tubular supports 82 and 8 Means is provided for preventing rotation of the supporting members 116 and 118 relative to their associated supports and for guiding the supporting members in smooth sliding manner along the axial extent of the supports. Such means includes the provision of a radially outstanding rib or rail 122 on each of the supports, the ribs extending substantially the full length of the supports and being formed on the face of the supports that faces the side frame bar 14. The supporting members 116 are axially split from one end to the other, so as to provide axial grooves or slideways 124, which slidably engage the sides of the rib or rail 122, thereby preventing relative rotation between the supporting members and the supports and insuring a free, sliding movement of the supporting members.

Means is provided for raising and lowering the supporting members in consort on their associated, upstanding and rigidified supports 82 and 84 and such means essentially comprises a hoisting arrangement. The hoisting arrangement, generally designated by the reference numeral 126, comprises an elongated rotatable shaft 128, which extends lengthwise of the base frame and is disposed parallel with and in adjacency with and inwardly of the side frame bar 14. The opposing ends of the shaft 128 are rotatably journaled in journaling means 130, which is supported by support brackets 132 that are attached to the adjacent standards 48, as shown in FIGURE 5. The shaft 128 lies below the side frame bar 14, as shown in FIGURE 2, and is provided on its end portions, adjacent the journaled ends, with drum means 134 and 136. The drum means are actually composed of annular plates 138 and 140, which are suitably fixedly circumposed on the end portions of the shaft and which are spaced apart and define with the circumferences of the end portions of the shaft the winding drums 134 and 136, on which elongated flexible elements, such as cables 142 and 144 are wound.

The cables 142 and 144 are controlled by the rotation of the actuating drum shaft 128 and the cables operate in consort to raise and lower the associated supporting members in an even, commonly moving manner, thus, the cable 142 is structurally related with the supporting memher 116 while the cable 144 is structurally connected to the supporting member 113. Since such structural arrangement of the cables with their associated supporting mem- 3 hers is the same, in each instance, a detailed explanation of the structural arrangement of the cable 142 with the support 82 and associated supporting member 116 will sufiice.

In this respect, as shown in FEGURES 4-6, the crossbar 24 is provided on its underside with a depending pair of cars 146, which carry a pin or axle 148, on which a pulley or sheave 150 is rotatably disposed for rotation about an axis, parallel to the longitudinal axis of the elongated mobile base frame 12. The flexible element 142 leaves off from the immediately adjacent drum or winch means 135 and passes under the pulley 150, which is disposed below the lower open end 86 of the support 82, so that the elongated element is almost completely enclosed and is completely and conveniently guided from the drum means 13% into the tubular support 82.

The flexible element 142 extends movably upwardly in the support 82, which is provided at its upper end portion 152, as shown in FIGURE 4, with an upper guide means 154, which is constituted by a rotatable pulley 156. The upper end portion 152 of the support 82 is formed with an axial end notch or cutout portion 15 8 on the face which carries the guide rib or rai 122. The pulley 154 is rotatably mounted on a pin or ale 159, fixed internally of the upper end portion and disposed diametrically thereof,

:ith the axis of the pulley 154 paralleling the axis of the pulley 150 and the axes being in substantially vertical alignment and being disposed parallel with the longitudinal axis of the base frame 12. The projecting portion of the pulley 154 which extends slightly beyond the internal diameter of the tubular support 32, does not extend beyond the radially projecting extent of the rib or rail 122, as can be appreciated from a consideration of FIGURES 1 and 3, so that the supporting members can move upwardly past and above the upper ends of the supports 82 and 34. Thus, the upper guide element or pulley 154, by virtue of the rib or rail 3.22 in the given, specific instance, is disposed entirely within the supporting or working area of the support 82, whereby it is possible for the sleeve-like supporting members 116 and 113 to ride over and above the pulleys and the upper ends of their associated supports 82 and 84.

The flexible element 142 passes over the pulley 154 and extends externally of the support and is attached at its outer end 162 to a hook means H4, which is in the form of a closed loop or eyelet, that is secured to a lateral projection 166 on the face 168 of the supporting member 116, adjacent its lower end. The book means 164 is provided on the face 168, which faces toward the end 18, so that the flexible elements or cables 142 and 1 4 are fixed to their associated supporting members 116'and 118 by anchoring hook-like means 164 that is provided on the faces of the supporting members that are directed toward the ends of the base frame 12 and are disposed in oppositely facing directions. Also, it is to be noted that the face 168 or, otherwise stated, the hoololike anchoring elements or means 164 are disposed substantially normal to the slotted faces of the associated supporting members, which face the side frame bar member 14. This permits the flexible elements to extend externally and be anchored to the supporting members in a manner so as to not interfere with the sliding movements of the supporting members on their associated supports and in a manner so that the flexible elements are not in any way impeded or interfered with by the platform assembly 120 nor do they olfer any obstruction to workmen on the platform assembly or to the handing of materials to workmen on the platform assembly 12!).

Means is provided for rotating the shaft 128, so as to control in consort the raising and lowering movements of the supporting members 116 and 118 for the platform assembly 120, such movements being controlled by the unison operation of the flexible elements 142 and 144. The actuating means for the shaft 128 comprises a pinion 1719, which is fixed on the shaft 128 and enclosed in a housing 172, that is supported by a bracket means which extends laterally inwardly from and is anchored to the side frame bar 14, as shown in FIGURES 5 and 6. An actuating shaft 174 is rotatably journaled in a bearing sleeve 176, which forms part of the housing and is provided with a worm gear 17 S enmeshed with the pinion 179 so as to rotate the shaft 128. The actuating shaft 174 terminates in an outer end 180, which is noncircul r, and which is adapted to receive a coupling socket 182 for a handwheel 184.

The handw-heel 184 is adapted to be manually rotated, so as to rotate the shaft 128, and through the enmeshed worm gear and pinions 17S and 17C} for thereby operating the drums 134 and 135, so as to control the hoisting or lowerin actions of the flexible elements or cables 142 and 144.

.V-hile the manually operated handwheel will work most efiiciently and will enable the scaffold to be produced and sold at a lower cost, it is to be understood that an electric motor can be substituted for the handwheel and can be mounted on the side frame bar 14 and have its armature shaft drivingly associated or connected with the actuating shaft 17 i or directly with the shaft 128, the motor being of any electrical type and being operated by storage batteries and the energization thereof being controlled by switch means positioned on the platform assembly 120 in an accessible manner so that workmen on the platform 8.356211 ly 128 can control, in a remote manner, the rotative movements of the shaft 128.

The platform assembly 126 comprises arms 186 and 188. The arms are in the form of angle irons, as shown in FIGURE 4, and project laterally from their associated supporting members. As shown in FIGURE 4, the arm 186, when the support 32 is in an upright vertical position and the supporting member 116 is operatively mounted thereon, under the control of the elongated flexible element 142, projects laterally from the supporting member and faces toward the side frame bar 16 or in the opposite direction from the rail and slide arangement. The arm 1% is of right angular, cross-sectional configuration, preferably being made from an angle iron, and, therefore, has a flat, substan 'ally horizontally disposed upper face 188 and a vertical face or flange 1%. An attaching plate 192 is formed on the inner end of the vertical face 195 and is secured, as by welding 194, to the associated supporting member 116. Thus, the arms are rigid with their associated supporting members.

An achoring or attaching angle iron 1% overlies the arm and has an upper face or side 198, which overlies the upper surface of the upper face 188 of the arm and a vertical flange 2%, which is formed with apertures 2&2 that are adjustably registrable with apertures 2% formed in the vertical side or flange of the arm and adapted to receive bolt or similar fastener assemblies 2116. The anchoring or attaching angle irons 196, which are bolted by the bolt assemblies 2% to the arms, support a horizontal platform 2%, which is made up of side by side, parallel planks 21H) that are held together by a frame assembly 212 which is fastened, as by welding 214, to the faces 198 of the anchoring angle irons.

A guard rail structure 216 is provided on the inner, longitudinally extending side of the platform, since the outer lon'ritudinal side edge portion of the platform will be in adjacency to a vertical structure, such as the well of a building and will not require any guard rail structure. The guard rail assembly 216 comprises an elongated, longitudinally extending handrail 218, which is attached by supporting arms 226 to the platform support 212, the lower ends of the arms 22% being pivoted by pivot pins 222 to upstanding ears 224-, as shown in FIG- URE 4. A locking, hinge-type brace 225 is pivotally interconnected between one of the planks and each of the supporting arms 22% for the handrail, as shown in FIG- URE 4.

As shown in FIGURE 7, spring-urged locking or hitching detents 228 are carried by the supporting members for automatic safety latching engagement with a series of vertically arranged springs 239 in the supports. The detents are manually releasable and constitute a safety factor in the event of malfunction of the hoisting means, such as breakage of one of the hoisting cables.

it can be appreciated, from a consideration of FIG- URE 8, that when the scaffold is not in use, the vertical brace rods 96, as, 168 and 11s are removed by simply removing the attaching pins therefor and the supports 82 and 34 are lowered into substantially or generally horizontal positions resting on the base frame and disposed in side-by-side relationship. The supporting members and arms are still carried by the supports and the detached brace rods can be placed on the base frame 12 so that the entire scaffold, in its knocked down or collapsed relationship, can be transported to another working site by a draft vehicle attached to either end of the mobile frame, as afore described.

When the supports are in upright positions, they are held in such positions by the brace rods and the flexible elements 142 and 144 are attached to the supporting members 116 and 118 so as to control the vertical movement thereof, with the platform assembly 120 attached to the arms. The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. A scaffold comprising an elongated base frame having opposing end sections, an elongated tubular support carried by the base frame adjacent each end section, means mounting the supports on the base frame for positioning of the supports in rigid upright positions and disposed substantially in alignment longitudinally of the base frame, each support having an upper and a lower end, a supporting member slidably sleeved on each support, a platform assembly carried by the supporting members and including a substantially horizontally disposed platform overlying the base frame and extending between the supports, rotatable winding means carried by the base frame, a pair of elongated flexible elements wound on and actuated by the winding means in synchronized fashion, a lower guide means disposed below the lower end of each support, an upper guide means carried by the upper end of each support, one of said flexible elements being passed under the lower guide means for one support and extending movably upwardly in the one support and being passed downwardly over the upper guide means on the one support externally of the support, the other of said flexible elements being passed under the lower guide means for the other support and extending movably upwardly in the other support and being passed downwardly over the upper guide means on the other support externally of the support, and means attaching the flexible elements to the supporting members for moving the supporting members in consort on their associated supports.

2. The invention of claim 1, wherein said upper guide means for each support is disposed entirely within the working cross-sectional area of the support so that the supporting members can extend above the upper ends of the supports.

3. The invention of claim 1, wherein said upper guide means for each support includes a rotatable pulley, means mounting the pulley in a vertical position at the upper end of the support so that the supporting members can be raised into uppermost positions extending upwardly above the upper ends of the supports.

4. The invention of claim 1, wherein said lower guide means for each support includes a pulley, means carried by the base frame for rotatably mounting the pulley in a vertical position below the lower end of the support.

5. The invention of claim 1, wherein said upper guide means for each support includes a rotatable pulley, means mounting the pulley in a vertical position entirely within the supporting area of the support, said lower guide means for each support including a rotatable pulley, means carried by the base frame for mounting said last pulley in a vertical position below the lower end of the support, said pulleys being rotatable about axes parallel to the longitudinal axis of the base frame.

6. The invention of claim 5, wherein said winding means includes an elongated shaft disposed parallel with the longitudinal axis of the base frame and extending substantially the length of the base frame, means mounting the shaft on the base frame for rotation, actuating means for rotating the shaft and means carried by the shaft adjacent each support and on which the flexible elements are disposed for movements in unison responsive to rotation of the shaft.

7. The invention of claim 6, wherein said last-named means includes a drum means on the shaft adjacent each support and disposed immediately adjacent the lower pulleys so that the flexible elements pass from the drum means to guided positions on the lower pulleys.

8. The invention of claim 7, wherein said base frame has a side and said shaft is positioned lengthwise of the base frame in adjacency to the side. I

9. The invention of claim 8, wherein said actuating means for the shaft comprises a pinion fixed on the shaft intermediate the drums, a drive shaft, means carried by the side of the base frame rotatably supporting the drive shaft transversely thereof, said drive shaft carrying a Worm gear enmeshed with the pinion and means for rotating said drive shaft.

10. The invention of claim 1, wherein steerable wheel assemblies are attached to each end section of the base frame and mobily support the base frame, draft connection means carried by each wheel assembly for detachable connection to a draft vehicle, said draft connection means being selectively employable so that the base frame can be drawn from either end section and means associated with each wheel assembly and the associated draft connection means for retaining the draft connection means in an inoperative position and rendering the associated wheel assembly non-steerable when the draft connection means on the opposite end section is in use.

11. The invention of claim 1, wherein said mounting means for the supports comprises means carried by the base frame and connected to the lower ends of the supports for mounting the supports for pivotal movement from an upright position into generally horizontally collapsed positions resting lengthwise on the base frame longitudinally thereof.

12. The invention of claim 12, wherein said supports are pivotally mounted in slightly offset relation longitudinally of the base frame so that in upright positions they are in substantial alignment considered lengthwise of the base frame but in collapsed positions they lie alongside each other on the base frame.

13. The invention of claim 1, wherein means is provided for preventing rotational movement of the supporting members relative to the supports and for guiding the supporting members in firm rectilinear sliding movements on the supports.

14. The invention of claim 1, wherein said supporting members have sides facing toward the end sections and opposing sides facing in opposite outward directions longitudinally of the base frame and said means attaching the flexible elements to the supporting members includes hook elements carried by said last sides adjacent the lower ends of the supporting members.

15. The invention of claim 14, wherein said platform assembly comprises an arm laterally projecting from each supporting member adjacent the upper end thereof and References Cited disposed transversely of the longitudinal axis of the base UNITED STATES PATENTS frame, said arms extending in the same direction substantially normal to h id carrying the hook elements and 657392 9/1900 Curley 92-145 being complementarily and cooperativ ly disposed, Said 5 $232; if- 1:3:3; platform having opposing en means femovably mount 3 5 11/1964 5 22 55 182-146 ing the platform ends on the arms so that the platform a 3,323,616 6/1967 Best 182--146 is supported thereby in a honzontal position and guard rail means associated with the platform. REINALDO P. MACHADO, Primary Examiner.

Claims (1)

1. A SCAFFOLD COMPRISING AN ELONGATED BASE FRAME HAVING OPPOSING END SECTIONS, AN ELONGATED TUBULAR SUPPORT CARRIED BY THE BASE FRAME ADJACENT EACH END SECTION, MEANS MOUNTING THE SUPPORTS ON THE BASE FRAME FOR POSITIONING OF THE SUPPORTS IN RIGID UPRIGHT POSITIONS AND DISPOSED SUBSTANTIALLY IN ALIGNMENT LONGITUDINALLY OF THE BASE FRAME, EACH SUPPORT HAVING AN UPPER AND A LOWER END, A SUPPORTING MEMBER SLIDABLY SLEEVED ON EACH SUPPORT, A PLATFORM ASSEMBLY CARRIED BY THE SUPPORTING MEMBERS AND INCLUDING A SUBSTANTIALLY HORIZONTALLY DISPOSED PLATFORM OVERLYING THE BASE FRAME AND EXTENDING BETWEEN THE SUPPORTS, ROTATABLE WINDING MEANS CARRIED BY THE BASE FRAME, A PAIR OF ELONGATED FLEXIBLE ELEMENTS WOUND ON AND ACTUATED BY THE WINDING MEANS IN SYNCHRONIZED FASHION, A LOWER GUIDE MEANS DISPOSED BELOW THE LOWER END OF EACH SUPPORT, AN UPPER GUIDE MEANS CARRIED BY THE UPPER END OF EACH SUPPORT, ONE OF SAID FLEXIBLE ELEMENTS BEING PASSED UNDER THE LOWER GUIDE MEANS FOR ONE SUPPORT AND EXTENDING MOVABLY UPWARDLY IN THE ONE SUPPORT AND BEING PASSED DOWNWARDLY OVER THE UPPER GUIDE MEANS ON THE ONE SUPPORT EXTERNALLY OF THE SUPPORT, THE OTHER OF SAID FLEXIBLE ELEMENTS BEING PASSED UNDER THE LOWER GUIDE MEANS FOR THE OTHER SUPPORT AND EXTENDING MOVABLY UPWARDLY IN THE OTHER SUPPORT AND BEING PASSED DOWNWARDLY OVER THE UPPER GUIDE MEANS ON THE OTHER SUPPORT EXTERNALLY OF THE SUPPORT, AND MEANS ATTACHING THE FLEXIBLE ELEMENTS TO THE SUPPORTING MEMBERS FOR MOVING THE SUPPORTING MEMBERS IN CONSORT ON THEIR ASSOCIATED SUPPORTS.

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