US2978062A

US2978062A - Variable height scaffold assembly

Info

Publication number: US2978062A
Application number: US666416A
Authority: US
Inventors: Camillo Eugene J Di; Donald I Smith
Original assignee: AIRSECO Inc
Current assignee: AIRSECO Inc
Priority date: 1957-06-18
Filing date: 1957-06-18
Publication date: 1961-04-04
Anticipated expiration: 1978-04-04

Description

April 1961 E. J. Dl CAMILLOI ETAL 2,978,062

VARIABLE HEIGHT SCAFFOLD ASSEMBLY Filed June 18, 1957 3 Sheets-Sheet 1 INVENTOR. EUGENE J. D! CAMILLO DONALD I. SMITH April 4, 1961 Filed June 18, 1957 E. J. DI CAMILLO ETAL VARIABLE HEIGHT SCAFFOLD ASSEMBLY 5 Sheets-Sheet 2 INVENTOR. EUGENE J. DI CAMILLO DONALD I. SMITH April 1951 E. J. Dl CAMILLO ETAL 2,978,062

VARIABLE HEIGHT SCAFFOLD ASSEMBLY a J ag VARIABLE HEIGHT 'SCAFFOLD ASSEMBLY N.Y., a corporation of New York Filed June18, 1957, Ser. No. 666,416

2 Claims (Cl. 181-1) Many construction and servicing operations, in par :ticular thoseinvolving maintenance of aircraft, require that thescaifolding from which the work is performed be "set at various heights. In the case of an airplane wing,

' United States Patent() Eugene J. Di Camillo, Lynbrook, and Donald I. Smith,

Oakda N Y asslgnors to Ausecoi Inc Brooklyn scaffold units mtegrated beneath an airplane wing to form as well as motion controlling system energized by the forces attendant lowering of the platform.

A representative embodiment of the invention from which the above and other features and objects of the invention will be readily apparent is described below having reference to the accompanying drawing in which:

Figure 1 is a view in sidefelevation showing a series of scaffold assembly. I Figure 2 is an enlarged view in end elevation of the scaifoldunit of Figure 1, isolated from its companion scaffold unit, and ,Figure 3 is an enlarged view inside elevation of a scaffold unit partially elevated and showing a portion of a second unit joined thereto.

Referring to the drawing, there are illustrated scaffold units 10, each including a base 11 preferably mounted on caster wheels 11a for portability, and a vertically movfor examplegtheportion of the wing nearest the fuse- I lageis generally closest to the ground, the wing extending upwardly at an angle moving toward the tip, and ,vari able height scaffold units of a portable nature have been developed to serve this need. Each variable height unit,

however, is necessarily limited in working space and maintenance and construction crews have adopted the technique of bridging the space between two or more scaffold units with temporaryplanking. Dangerous work= ing conditions result. Moreover, presently used variable height scaffolds are in the form of a platform carried at the free end of a pivoted truss assembly adapted to he swung upwardly from a supporting base in a large are. This results in displacement of the platform longitudinally as it is swung upwardly, and it is often necessary to reposition theentire. assembly once the platform is elevated.

Both personnel and equipment are endangered by this able platform 12 joined to the base ll through a lifting truss assembly indicated generally by the numeral 13. The lifting truss 13 can take the form of a pantograph type linkage including, working from the base upwardly, a first pair of beams 14 and 15 (best seen in Figure 2) hinged through pivotal connections 14a and 15a to upstanding U-shaped'lugs 16 and 17 afiixed to the base 11. A second pair of beams 18 and 19 are'also hinged to the base 11 through pivotal connections 18:: and 19a, re= spectively, including

upstanding U-shaped lugs

20 and 21, also fixed to the base. The upper ends of the'beams 14 'and 15 are hinged through pivotal connections 14b and 15b, respectively, to the lower ends of a third pair ng f beams 22 and 2 3, the upper ends of which are in turn hinged through pivotal connections 22a and 23a to the platform "12, the coupling to the platform being com pleted through downwardly facing U-shaped.

lugs

24 and 25, respectively. The upper ends of the beams18 and 19 are similarly hinged through pivotal connections 18a and 19a to the lower ends of

beams

26 and 27, respectively, which are in turn hinged at their upper ends to the'plat form 12 through

pivotal connections

28 and 29, the latterincluding downwardly facing U-shaped lugs '30 'and 31;

Another object of the invention is to provide an adjustable scaffold which is stable in all positions of adjustment. Another object of the invention is to provide a scaffold assembly which entirely dispenses with the need for makeshift bridging planking in elevated positions.

' In accordance with the present invention, there is provided a scaffold assembly including a platform mounted for straight vertical movement relative to a supporting base, which can be of the Wheeled variety for portability. Pivotally attached to the platform is a stair assembly,theopposite end of which rests on the ground at a" point spaced from the platform. The grounded end of the stair assembly includes-a ground support enabling it to be readily carried along with the portable support base and also to shift inwardly along the ground as the platform rises from a fixed location, the stair treads being individually pivoted and coupled to control linkage so that they are at all times in a horizontal plane. The design of the scaffold units issuch that two or more can be readily integrated by joining the normally grounded end of orient the stair assemblies to the platform of "anotherscaffold unit. In this fashion the stair treads, now disposed'horizontally-in a common plane, afford anelongated working-space between two scaffold units, the entire elevated working space being fully protected by fixed railings, upstanding margins and other safety features.

Joined in the pivotal connections 18a and 19a, respectively, are bracing

beams

32 and 33, the lower ends of which are hingedto the

beams

14 and 15, respectively; in'pivotal

connections

34 and 35 near the lower ends of the

beams

14 and 15. Similarly, a pair of

bracing beams

36 and 37 are joined at theirlower ends in the an amount corresponding approximately to the spacing of the

pivotal connections

34 and 35 from the lower ends of the

beams

14 and 15. For lateral stabilization, cross bridging is inserted between beams 18 and 19, in the form of a pair of

traverse members

40 and 41 bridged by a diagonal member 42. Similarly, the upper pair of

beams

26 and 27 are reinforced by

cross members

43 and 44 and a diagonal member 45. V v e In order to raise the platform 12 from the supporting base 11, lift means in the form of a jack 46 is disposed between a cross member 46a and a corresponding cross member 11a on the base 11; The member 46a is linkedto thebeams 14, 1 8 at one of its ends and to the beams 15, 19 at its other end, pivotal connectionsbeing effected at each joint. The jack is adapted to be actuated by means of a control assembly 47 mountedjon the plat- Also, in accordance with'the invention, the vertically movform 12 and coupled to the l through high-Pressure able platform can be'power driven through the agency tubing 48 which can be either flexible throughout or f a pneumatic: drive including an energy recovering flexible at its curved portions to accommodat 9 Patented Apr. 4, 1961 i tical motion. The control assembly 47 can take the form of a pressure source, such as a storage tank or a pump, actuated by a handle 47a, and suitable valve control means, not shown, for directing fluid to or from the jack.

In order to secure the movable platform 12 in any one of its range of positions, locking means in the form of a slotted and notched arm 64 is'pivotally connected to the beam 22 of one end with a pin 65 fixed to the platform 12 being received in its notched slot. As the platform rises, the locking means automatically secures it in successively higher positions. form, it is necessary that the operator, in addition to manipulation of the control assembly 47, hold the looking means in its inoperative position freeing the pin 65 from the notches. A safety catch can be engaged with the arm 64 to prevent accidental release. When the scaffold is in use, it is advisable to disable the caster wheels of the base. To this end, anchoring pads are provided to engage the ground, the pads preferably being carried by extendable arm means for supplementary support against tipping.

The platform 12 is protected on two of its sides by

handrails

66 and 67 and on its third side by the removable chain 68. The fourth side is the approach through which access to the platform is gained, this side being the terminal or upper end of a stairway assembly indicated generally by the numeral 69. The, assembly 69 includes a pair of stretcher or carriage beams 70 hinged at their upper ends to the platform 12 in pivotal connections 71 and joined at their lower ends by fixed crosspiece 72 in which caster wheel means 73 are mounted. Each stretcher 70 carries a hand or safety rail 74, and, at the upper end of the side rails 74, the

rails

66 and 67 on the platform 12 are formed with extensions 66a and 67a bridging the generally triangular space therebetween the extensions being slightly laterally offset from the hand rails 74 for reasons presently to be described. The stretchers 70 carry a series of treads 75 in the form of plate members hingedly connected to the risers by means of pivotal connections 76 adjacent their inner edges. 77, the respective free ends of which are pivotally connected to a common control bar 78 extending generally parallel to the stretchers 70 and terminating in a pivotal connection 79 (see Figure 2) to a depending anchoring To lower the platmon horizontal plane, forming a continuous surface from which repair and maintenance operations can be conducted. The side rails, without repositioning or alteration, fully protect the horizontal runway. In addition the pivotal connection between each stair tread and the stretcher 70 is such that an upstanding safety lip or edge results.

In certain cases, corresponding platforms 12 of two integrated units may be necessarily disposed at slightly different levels, as might be the case, for example, when servicing an airplane wing. Normally, a significant variation in-heights would break up the coplanar arrangement of the stair treads which form the surface of the bridging member between the two units. In accordance with the present invention, the pivotal connection 79 between the stair tread control bar 78 and the fixed depending lug 80 can be disabled to afford lost motion in either direction over a distance determined by the length of a slot 84 in the member 80. By shifting the axis of the pivotal connection 79 along the length of'the slot 84, the stair treads 75 can be maintained coplanar not only in a horizontal plane, but in the slightly angled plane of the stretchers 70, thus forming an inclined but smooth runway between platforms. In those cases in which the platform 12 is relatively close to the ground, the horizontal positioning of the stair treads 75 can be shifted into the plane of the stretchers to form a Each tread 75 has secured thereto a rocker arm lug 80 secured to the platform 12. The stair tread connections are such that for every angular position of the stretchers 70, the stair treads 75 are held in a horizontal position. In this fashion, as the platform 12 is lifted, the stairway remains useable at all times, the grounded end of the stairway rolling inwardly on its wheel means 73 as the platform rises.

In the event two staging units 10 are used together, the stairway assembly 69 of one unit is convertible in accordance with the present invention into a bridging platform by swinging it upwardly into the horizontal plane of the platform 12 and securing the normally grounded end thereto. As illustrated in Figure 2, for example, the stair and platform assembly 69, shown at the upper left-hand portion of the figure and constituting a stair assembly identical to that 69 of the staging unit 10,

has been coupled to the platform 12 by means of a cou pling indicated generally by the numeral 80. The coupling 80 includes an L-shaped channel 81 adjacent the normally grounded end of the stair assembly and received in a channel 82 formed at the edge of the platform 12. It will be recalled that this edge of the platform is normally bounded by the removable chain 68. Preferably, a rubber bumper 83 is secured to the exposed edge of the platform 12 on three sides both to protect equipment being serviced from damage and to tighten the coupling 80 between mated staging units. With the stair assembly 69' disposed in a horizontal plane, each of the stair treads 75 will be disposed in a comsmooth ramp leading from the ground to the platform 12. Thus, if desired, heavy equipment can be wheeled on a dolly to the platform 12 before it is raised. Also, the inclined ramp can be used as the last stage of a series of the ramp section, not part of the illustrated equipment, leading from the ground to the raised platform.

It will be understood that any number of basic units can be combined to form, for example, stagings extending the entire length of an airplane wing or extending all around a building under construction and from which masons, for example, can work, raising the platforms as one as their work progresses upwardly. While the invention has been illustrated and described above having reference to a particular embodiment thereof, it will be understood that it can take various other forms and arrangements within the scope of the present invention which should not therefore be regarded as limited except as defined in the following claims.

We claim:

1. A scaffold assembly comprising a supporting base, a work platform, linkage means between the base and the platform for guiding the platform in vertical motion, jack means for raising and lowering the platform, access stairway means including a bank of stair treads, means to pivot ally secure said bank at its upper end to said platform;

means to support the lower end of said bank on the ground to move toward and away from the base as the platform is respectively raised and lowered, said treads each being pivotally mounted in the bank for swinging movement on a horizontal axis, and control linkage means joined to each of said treads and responsive to pivotal movement of the bank relative to the platform to maintain the threads in a horizontal plane, said stairway including first securing means adjacent its normally grounded end remote from the platform, said platform including on an edge other than that of the pivotal connection of the stairway, second securing means complementary to that of the stairway, whereby two laterally spaced apart scaffold assemblies can be integrated by uniting the first and second securing means disposed respectively on the platform of one assembly and the stairway of the other assembly to form a bridging platform between the two vertically movable platforms, said stairway tread control means driving the treadsof the bridging stairway into coplanar relationship.

-2. A scaffold assemblycomprising a supporting base,

a work platform, linkage means between the base and the platform for guiding the platform in vertical motion, jack means for raising and lowering the platform, access stairway means including a bank of stair treads, means to pivotally secure said bank at its upper end to said platform, means to support the lower end of said bank on the ground to move toward and away from the base as the platform is respectively raised and lowered, said treads each being pivot-ally mounted in the bank for swinging movement on a horizontal axis, and control linkage means joined to each of said treads and responsive to pivotal movement of the bank relative to the platform to maintain the treads in a horizontal plane, including lost motion means selectively adapted to disable the control means for the treads to maintain the treads in a horizontal plane, whereby the stair treads can be swung into coplanar relationship at angles slightly above or slightly below the horizontal.

References Cited in the file of this patent UNITED STATES PATENTS Peterson June 17, 1884 Fellows June 13, 1922 Havens June 3, 1930 Bird July 4, 1933 Bailey Ian. 23, 1934 Swaisgood Nov. 7, 1944 Conrad Apr. 5, 1949 Ross May 31, 1949 Sensenbaugh Jan. 13, 1953 Middendorf June 12, 1956 Cash July 2, 1957 FOREIGN PATENTS Great Britain Sept. 26, 1928