(Not Applicable)
(Not Applicable)
This invention relates generally to the field of scaffolding and more particularly to an adjustable scaffold base for allowing scaffold towers to be erected above ground level obstructions.
Traditionally, it has generally been difficult to change light bulbs or perform other high-elevation indoor maintenance tasks, such as painting or repairing ceiling surfaces, in churches, theaters, stadiums or other buildings that have high ceilings and that also have permanently-fixed ground level obstructions, such as pews or other fixed seating structures. Traditional frame-scaffolding that would normally be erected to facilitate high-elevation maintenance tasks is generally inappropriate for environments that include ground level obstructions because the spacing between the frame legs of such scaffolding typically does not match the spacing around pews or other large or irregularly-shaped obstructions. Even if the frame spacing of traditional scaffolding could be made to coincide with the spacing around ground level obstructions, the necessary cross-bracing between the scaffold frames would hit the obstructions. Furthermore, the legs supporting the scaffolding may have to bear on surfaces that can be 45 inches or more out of level with one another, whereas typical scaffolding leveling jacks that are normally employed to accommodate uneven surfaces only have about 14 inches of vertical adjustment. Still further, typical scaffold frames are only wide enough to support freestanding structures that are approximately 20 feet tall, which is not tall enough to reach the ceilings of many buildings.
It is possible for scaffold companies to build tube-and-clamp scaffolding structures that accommodate environments that present immovable, ground level obstructions, but the cost of labor and equipment to erect such structures is often prohibitively expensive. It would therefore be desirable to provide a relatively low-cost, highly adjustable scaffolding system that can be erected around immovable, ground level obstructions for accommodating high-elevation tasks such as replacing light bulbs and painting or repairing ceiling surfaces.
It is therefore an object and feature of the present invention to provide a low-cost means for allowing a conventional scaffold tower to be erected in a manner that avoids ground level obstructions. It is a further object and feature of the present invention to provide such a means that is suitable for supporting a conventional scaffold tower having a height that is sufficient for allowing a worker to reach the ceiling of a church or other such building having high ceilings. It is a further object and feature of the present invention to provide such a means that can be easily moved while still fully erected.
In accordance with the present invention, there is provided an adjustable scaffold base for supporting a conventional scaffold tower at an elevated position above ground level obstructions. The scaffold base includes four elongated, upstanding primary legs that are spaced apart in a parallel relationship with one another. A first lateral beam extends between two of the primary legs in a perpendicular relationship therewith, and a second lateral beam extends between the other two of the primary legs in a perpendicular relationship therewith and in a parallel relationship with the other lateral beam. Each primary leg extends through a primary leg sleeve that is rigidly affixed to an adjacent end of the primary leg's respective lateral beam. Each primary leg sleeve can slidably move along its respective primary leg, thereby allowing each lateral beam to move up and down along the length of its respective pair of primary legs. Each primary leg sleeve can be removably secured at a plurality of positions along the length of its respective primary leg by extending a pin through a pair of axially-aligned positioning holes formed in the primary leg and its respective primary leg sleeve.
First and second frame beams extend across, and are removably secured to, the first and second lateral beams in a perpendicular relationship therewith and in a spaced, parallel relationship with one another. Each frame beam can be removably secured at a plurality of positions along the length of each lateral beam. A pair of frame posts extends upwardly from each of the frame beams in a perpendicular relationship therewith and in a spaced relationship with one another for engaging and rigidly supporting the scaffold frames of a conventional scaffold tower. A scaffold tower can thus be erected and supported atop the scaffold base, with the scaffold base straddling and avoiding ground level obstructions, such as church pews or other fixed, ground level structures.
The erected scaffold base and scaffold tower can be easily moved by inserting four auxiliary legs into vertically-oriented auxiliary leg sleeves that are rigidly affixed to the ends of the frame beams. Conventional casters are mounted to the bottom ends of the auxiliary legs. All of the auxiliary legs are lowered within their respective auxiliary leg sleeves until their casters are in contact with the surface upon which the scaffold base stands. The positions of the auxiliary legs are then secured by inserting pins through aligned pairs of positioning holes in the auxiliary leg sleeves and the auxiliary legs. Each of the primary legs is then raised within its primary leg sleeve and is secured at an elevated position, thereby leaving the scaffold base and the scaffold tower supported solely by the auxiliary legs and casters. The scaffold base can then be rolled upon the casters to a desired location, after which the primary legs can again be lowered and secured.
a is an exploded, perspective view illustrating the legs, feet, and lateral beams of the scaffold base present invention.
b is a perspective view illustrating the assembled legs, feet, and lateral beams of the scaffold base of the present invention.
a is a perspective view illustrating the assembled legs, feet, lateral beams, and frame beams of the scaffold base of the present invention.
b is a detail view illustrating the mounting bracket of a frame beam of the present invention.
a is a partially exploded perspective view illustrating the legs, feet, lateral beams, frame beams, and cross brace of the present invention.
b is a perspective view illustrating the fully assembled scaffold base of the present invention.
a is a front view illustrating the scaffold base of the present invention with the lateral beams mounted to the outsides of the mounting brackets of the frame beams.
b is a front view illustrating the scaffold base of the present invention with the lateral beams mounted to the insides of the mounting brackets of the frame beams.
In describing the preferred embodiment of the invention which is illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, it is not intended that the invention be limited to the specific term so selected and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose.
This application claims the benefit of U.S. Provisional Application No. 61/351,320, which is incorporated herein by reference.
Referring to
For the sake of convenience and clarity, terms such as “top,” “bottom,” “up,” “down,” “inwardly,” “outwardly,” “lateral,” and “longitudinal” will be used herein to describe the relative placement and orientation of various components of the invention, all with respect to the geometry and orientation of the fully assembled scaffold base 10 as it appears in
Referring to
Referring to
Each lateral beam 16 and 18 terminates at each of its longitudinal ends in a primary leg sleeve 32a-d that is formed of a short segment of square steel tubing that is rigidly connected to its respective lateral beam 16 and 18, such as by welds, in a perpendicular relationship therewith. Each primary leg sleeve 32a-d has positioning holes 34 formed through it that are spaced on 1.25 inch centers along the sleeve's length. Flat steel segments 36a-d are preferably welded to the primary leg sleeves 32a-d and to their respective lateral beams 16 and 18 for enhancing the strength and rigidity of the connections between the primary leg sleeves 32a-d and the lateral beams 16 and 18. Although incorporation of the leg sleeves 32a-d is preferred, it is contemplated that the leg sleeves 32a-d can be omitted and that the vertically-oriented holes can alternatively be formed through the lateral beams 16 and 18 for accepting the primary legs 14a-d (as described below).
Referring to
The bottommost ends of the primary legs 14a-d fit over and axially engage the necks 28a-d of the feet 12a-d, thereby rigidly supporting the primary legs 14a-d in a vertical orientation. Alternative embodiments of the scaffold base 10 are contemplated in which the primary legs 14a-d are permanently mounted to the lateral beams 16 and 18 in a fixed position and are not slideably adjustable relative thereto.
In order to adjust the heights of the lateral beams 16 and 18, such as to a height above fixed, ground level obstructions (described in greater detail below), the primary leg sleeves 32a-d of each lateral beam 16 and 18 can be slid upwardly or downwardly along their respective primary legs 14a-d. Since each lateral beam 16 and 18 is fixed at both of its longitudinal ends to a respective, vertically-oriented primary leg 14a-d in a substantially perpendicular orientation therewith, the lateral beams 16 and 18 will remain in a substantially horizontal orientation as they are moved vertically along their respective primary leg-pairs. After each lateral beam 16 and 18 has been moved to a desired height at least one of the positioning holes 34 in each primary leg sleeve 32a-d is brought into axial alignment with a closest positioning hole 38 in a respective primary leg 14a-d. Pins 40a-d are then inserted through each pair of aligned positioning holes 34 and 38 to secure the primary leg sleeves 32a-d against vertical movement along the primary legs 14a-d, thereby fixing the lateral beams 16 and 18 at the desired height. The pins 40a-d are preferably standard, spring-loaded, positive locking pins having an outer diameter that is slightly smaller than the diameter of the respective holes through which they pass. However, all other types of fastening means, such as screws, bolts, rivets, clamps, non-spring-loaded pins, and friction mounts are also contemplated.
Referring to
A pair of positioning brackets 50a-d is rigidly mounted to the underside of each frame beam 20 and 22, with each positioning bracket 50a-d positioned about 4.5 inches inward from a nearest longitudinal end of the frame beam 20 and 22. The positioning brackets 50a-d preferably measure 6 inches long and are formed of rectangular blocks of steel. Each positioning bracket 50a-d has a 0.625 inch diameter positioning hole (not within view) extending horizontally through it for receiving a threaded bolt of a slightly smaller diameter (as described below), as best shown in
When operatively positioned, the frame beams 20 and 22 rest on top of, and extend perpendicularly across, the lateral beams 16 and 18, with each lateral beam 16 and 18 positioned inward of the auxiliary leg sleeves 42a-d and outward of the positioning brackets 50a-d of the frame beams 20 and 22 as best shown in
Referring to
Referring to
If the scaffold base 10 must be positioned on a sloped surface, such as on an auditorium aisle way or on a wheelchair ramp, it is contemplated that conventional swivel plates 80a-d can be substituted for one or more of the feet 12a-d, as shown in
Referring to
To move the scaffold base 10, all of the auxiliary legs 90a-d are lowered until their respective casters 92a-d are in contact with, or are nearly in contact with, the surface upon which the feet 12a-d of the scaffold base 10 rest. The vertical positions of the auxiliary legs 90a-d are then secured. Each of the primary legs 14a-d is then raised within its primary leg sleeve 32a-d and is secured at an elevated position, thereby leaving the scaffold base 10 and the scaffold tower supported solely by the auxiliary legs 90a-d and casters 92a-d. Alternatively, the primary legs 14a-d can be entirely removed from their respective primary leg sleeves 32a-d (which requires removal of the feet after the primary legs 14a-d have been raised a short distance off the support surface). The scaffold base 10 can then be rolled upon the casters 92a-d to a desired location. Since the auxiliary legs 90a-d are spaced only four feet apart from one another, the scaffold base 10 can easily fit through most aisle ways and other narrow areas while the elevated lateral beams 16 and 18 and primary leg sleeves 32a-d move above ground level obstructions (i.e., if the primary legs 14a-d have been entirely removed from, or sufficiently raised in, the scaffold base 10). Once the scaffold base 10 has been moved to a desired location, the primary legs 14a-d and feet can be reinstalled and repositioned to support the scaffold base 10 in the manner described above, and the auxiliary legs 90a-d and casters 92a-d can be raised or entirely removed from the scaffold base 10.
This detailed description in connection with the drawings is intended principally as a description of the presently preferred embodiments of the invention, and is not intended to represent the only form in which the present invention may be constructed or utilized. The description sets forth the designs, functions, means, and methods of implementing the invention in connection with the illustrated embodiments. It is to be understood, however, that the same or equivalent functions and features may be accomplished by different embodiments that are also intended to be encompassed within the spirit and scope of the invention and that various modifications may be adopted without departing from the invention or scope of the following claims.
This application claims the benefit of U.S. Provisional Application No. 61/351,320 filed Jun. 4, 2010.
Number | Date | Country | |
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61351320 | Jun 2010 | US |