Scaffolding system

Abstract

A multi-level construction scaffold comprises a pair of H-shaped end frames spaced by horizontal guard rails. The guard rails are pivotally connected at opposed ends thereof to the end frame members, thereby allowing the guard rails to pivot in parallel when one of the frame member is lifted relative to the other. Each end frame includes a pair of uprights interconnected by a horizontal platform support located at a distance below the guard rails engaged with the end frames. In this way, the safety guard rails of a next level to be erected can be installed directly from the underlying level.

Description

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to scaffolding of the type used in the construction of buildings and, more particularly, to scaffolding assemblies wherein safety guards of an upper floor level can be installed from an underlying floor level.

[0003] 2. Description of the Prior Art

[0004] Temporary scaffolds are often erected alongside of buildings to enable work to be done on the building's exterior. Such construction scaffolds typically comprise a pair of inverted U-shaped lower trusses for supporting a work platform and a pair of similar upper trusses above the platform and having a plurality of guard rail posts supporting a plurality of horizontal safety guard rails for protecting operators from falling from the platform. With this type of arrangement wherein the platform is installed at the upper end of the lower trusses and the associated guard rails are mounted to the trusses of the next scaffolding level, it is not possible to install the guard rails of a given level before accessing the platform of this level. There is thus a risk that the operator falls from the platform while erecting the scaffold. Consequently, regulations requiring that the operator be strapped to the structure while building up the scaffold have been imposed. Despite the regulations and the relatively high risk of accidents, the operators often do not strap themselves to the scaffolding structure.

[0005] There is thus a need for a new scaffolding system wherein the safety guard rails of a scaffold which is being erected can be installed from the already erected underlying scaffolding level so that the operator stepping on the next floor level will be already protected from falling by the pre-installed guard rails.

SUMMARY OF THE INVENTION

[0006] It is therefore an aim of the present invention to provide a new scaffolding system in which the guard rails of a next scaffolding level to be erected can be installed from an underlying level.

[0007] It is also an aim of the present invention to provide a method by which a scaffold can be erected in a safe and simple way.

[0008] Therefore, in accordance with the present invention, there is provided a scaffold of the type used in the construction of buildings, comprising a first work platform supported at opposed ends thereof by a first pair of trusses, each of said trusses having a pair of uprights having top and bottom ends, said uprights being interconnected by a work platform support extending horizontally between said uprights at a location intermediate the top and bottom ends thereof, and connections on said uprights above said work platform support for pivotally connecting at least one guard rail to said first pair of trusses above said first work platform.

[0009] In accordance with a still further general aspect of the present invention, there is provided a multi-level construction scaffolding comprising at least first and second levels, each of said first and second levels comprising a work platform supported at opposed ends thereof by a pair of generally H-shaped trusses interconnected by a pair of guard rails extending above said work platform, each truss having a pair of uprights interconnected to each other at a location intermediate their top and bottom ends by a horizontal platform support member upon which the platform rests, wherein the guard rails and the work platform of a same level are supported by the same pair of H-shaped trusses.

[0010] In accordance with a still further general aspect of the present invention, there is provided a method of erecting a multi-level scaffolding structure, comprising the steps of: erecting a first scaffolding level comprising first and second end frames interconnected by bracing, mounting a third end frame on top of said first end frame, pivotally connecting a first end of a guard rail to said third end frame, pivotally connecting a second end of said guard rail to a fourth end frame, lifting said fourth end frame on top of said second end frame, thereby causing said guard rail to pivot upwardly from an inclined position to a substantially horizontal position between said third and fourth end frames, and mounting a work platform to said third and fourth end frames below the already installed guard rail of the second scaffolding level.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Having thus generally described the nature of the invention, reference will now be made to the accompanying drawings, showing by way of illustration a preferred embodiment thereof, and in which:

[0012] FIGS. 1 to 7 are perspective views illustrating the various steps that have to be followed for erecting a scaffolding structure in accordance with a preferred embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] FIGS. 1 to 7 illustrate a scaffolding system 10 whereby an operator can install the guard rails of a next level before accessing it, thereby greatly improving the operator's safety while assembling the scaffolding. As will be seen hereinafter, the scaffold guard rails are pivotally connected at a first end thereof to an already installed truss and at a second end thereof to a not yet installed second truss so that when the second truss is lifted in position onto an already installed truss of the underlying scaffolding level, the guards pivot to a horizontal position above the floor of the scaffold level that is being erected.

[0014] More particularly FIG. 7 illustrates a multi-level scaffold 10 comprising first and second scaffold levels 12 and 14 adapted to be temporarily mounted alongside of a building's wall. The levels 12 and 14 are provided with respective vertical frames or H-shaped trusses 16/18 and 20/22. Each H-shaped truss 16, 18, 20 and 22 includes a pair of uprights 24 and 26 interconnected by a work platform support 28 extending horizontally between the uprights 24 and 26. As opposed to conventional inverted U-shaped trusses wherein the work platform support is provided at the very upper end of the uprights 24 and 26, the work platform support 28 is located approximately midway between the top and bottom ends of the uprights 24 and 26. According to the illustrated embodiment, the platform support 28 is in fact located in the lower haft portion of the uprights 24 and 26. As will be seen hereinafter, lowering the position of the work platform support 28 advantageously allows installing the safety guard rails of a next level to be erected from the already installed underlying scaffold level.

[0015] Each H-shaped truss 16, 18, 20 and 22 further includes a pair of diagonal reinforcing members 30 extending from the lower end portion of opposed uprights 24 and 26 to the work platform support 28. The reinforcing structure further comprises a horizontal member 32 extending between the diagonal members 30 just below the work platform support 28. Horizontal struts 34 are also provided between the diagonal members 30 and the associated upright 24/26.

[0016] The uprights 24 and 26 and the work platform support 28 are preferably made of steel tubing whereas the diagonal members 30, the horizontal member 32 and struts 34 are preferably made of extruded steel. All these members are fixedly secured together as by welding.

[0017] The top ends of uprights 24 and 26 are provided with reduced diameter segments 36 that are sized to fit into the lower tubular portions of the uprights of the next truss, thereby allowing the trusses to be stacked into towers. To secure the trusses together, the reduced diameter segments 36 and the lower tubular portions of the uprights are provided with transversal registering holes (not shown) for receiving a lock pin (not shown).

[0018] First and second level platforms 38 and 40 are respectively supported at opposed ends thereof by the platform supports 28 of the first level trusses 16 and 18 and the platform supports 28 of the second level trusses 20 and 22. A ladder 42 is mounted between the first platform 38 and the second platform 40 for allowing an operator to climb to the second platform 40 from the first platform 38. The ladder 42 is hooked at its upper end to one of the platform support 28 on the second level 14. A trap 44 is provided in the second platform 40 adjacent the upper end of the ladder 42 for allowing the operator to have access to the second platform 40.

[0019] Top and intermediate vertically spaced-apart gravity locks 46 and 48 are provided on the upper haft portion of each upright 24 and 26 to provide for the installation of pairs of guard rails 52 between the first level trusses 16/18 as well as between the trusses 20/22 of the second level. Each gravity lock 46/48 comprises a pivot pin 50 projecting horizontally from an upright towards the other upright of the same truss.

[0020] Each guard rail 52 is provided in the form of a bar having opposed flattened end portions, each of which defines a hole for allowing the guard rail 52 to be pivotally engaged onto the pivot pins 50.

[0021] A bottom gravity lock 54 is provided on each upright 24/26 just below the platform support 28 for releasable engagement with cross braces 56 extending between the trusses of a same level. Each cross brace 56 is releasably connected at a first end thereof to the bottom gravity lock 54 of a given upright and at a second end thereof to the top gravity lock 46 of the opposed facing uprights. Accordingly, the top gravity locks 46 not only act as the pivot points for the top guard rails 52 but also act as the top anchoring points for the cross braces 56.

[0022] It is understood that when the scaffold is erected along a building wall, guard rails 52 does not have to be installed on both the front and the rear sides of the scaffold 10. Indeed, as illustrated in FIGS. 1 to 7, they can be installed only on the front side of the scaffold.

[0023] Referring now to FIGS. 1 to 7, the procedures for erecting the scaffold 10 will now be described in greater details.

[0024] As shown in FIG. 1, the first scaffold level 12 is first erected by first appropriately positioning on the ground a number of adjustable jacks 60. A first truss 16 is then installed in position on a first pair of jacks 60. Then, a first pair of cross braces 56 is connected at one end thereof to the already installed truss 16, one brace being connected to the top gravity lock 46 while the other is connected to the bottom gravity lock 54 of the front upright 26 of the already installed truss 16. Thereafter, a second truss 18 is installed on a second pair of jacks 60′ and the second opposed ends of the cross braces 56 are connected to the bottom and top gravity locks 54 and 46 of the front upright 26 of the second truss 18 so as to define a X at the front side of the first level of the scaffold 10. After having installed the cross braces 56, the first platform 38 can be placed onto the platform supports 28 of the already installed trusses 16 and 18. Once the platform 38 has been properly leveled through the used of the jacks 60 and 60′, the horizontal guard rails 52 are connected at opposed ends thereof to the top and intermediate gravity locks 46 and 48 of the trusses 16 and 18. As shown in FIG. 1, further trusses and work platform can be added in series to the first scaffolding level in order to provide the desired length of work platform along the building wall.

[0025] Once the first level 12 has been erected as described hereinbefore, the first truss 20 of the second level 14 is placed in position on the already installed first truss 16 of the first level 12. Then, while the operator is still on the work platform 38 of the first level 12, two rail guards 52 are respectively pivotally engaged at one end thereof with the pins 50 of the top and intermediate gravity locks 46 and 48 provided on the front upright 26 of the first truss 20 of the second level.

[0026] As shown in FIG. 2, the two guard rails 52 are then respectively pivotally connected to the top and bottom gravity locks 46 and 48 of the not yet installed second truss 22 of the second level 14. Thereafter, the truss 22 is lifted in position on top of the already installed second truss 18 of the first level 12, thereby causing the second level guard rails 52 to pivot from an inclined position to a horizontal position above the work platform support 28 of the trusses 20 and 22, as shown in FIG. 3. This results in the guard rails 52 of the second level 14 being installed from the first floor level 12 before the second level platform 38 be installed.

[0027] Once the guard rails 52 of the second level 14 have been installed, a cross brace 56 is installed between the trusses 20 and 22 as per the way described hereinbefore with respect to the cross braces 56 of the first level 12. As shown in FIG. 4, further trusses, guard rails and braces can be mounted in series on the second level 14 by following the same procedure.

[0028] As shown in FIG. 5, the next step consists of installing the work platform 38 of the second level 14. The work platform 38 is hooked at opposed ends thereof to the platform supports 28 of the trusses 20 and 22.

[0029] As shown in FIG. 6, the ladder 42 is subsequently hooked onto the platform support 28 of the truss 22 for allowing the operator to access the second floor level of the scaffold. As can be appreciated from the drawings and the above described procedure, the operator will already be protected against falling from the scaffold when he/she will step on the second floor level platform 38.

[0030] Finally, as shown in FIG. 7, a second work platform can be mounted in series to the first platform 38 of the second level as per the way described above.

[0031] The same steps must be followed for installing other levels.

[0032] The present invention is not limited to the illustrated embodiment and various changes can be made in the arrangement and design of the trusses, the guard rails and the cross braces without departing from the spirit of the present invention.

Claims

1 to 7. (cancelled)

8. A multi-level construction scaffolding comprising at least first and second levels, each of said first and second levels comprising a work platform supported at opposed ends thereof by a pair of generally H-shaped trusses interconnected by a pair of guard rails extending above said work platform, each truss having a pair of uprights interconnected to each other at a location intermediate their top and bottom ends by a horizontal platform support member upon which the platform rests, wherein the guard rails and the work platform of a same level are supported by the same pair of H-shaped trusses.

9. A multi-level construction scaffolding as defined in claim 8, wherein the two guard rails are respectively engage with first and second vertically spaced-apart pivot points provided on each truss at a distance above said platform support member thereof.

10. A multi-level construction scaffolding as defined in claim 9, wherein at least one of said first and second levels further includes a diagonal brace interconnecting the trusses of a same level, and wherein said diagonal brace extends from one of said first pivot points of a first one of said trusses, said diagonal brace being connected at an opposed end thereof to a third pivot point provided below the platform support member of a second one of said trusses.

11. A multilevel construction scaffolding as defined in claim 8, wherein each of said trusses includes a pair of opposed diagonal members extending upwardly from said uprights to said platform support member.

12 to 14. (cancelled)