Field of the invention

[0001 ] The present invention generally finds application in the field of scaffolding for the building industry and particularly relates to a connection assembly for connecting guard rails to uprights in a rigid scaffolding.

[0002] The invention also relates to a method of assembling a rigid scaffolding comprising such connection assembly.

Background art

[0003] Scaffolds have been long known, in the fields of building and construction, to comprise a plurality of uprights and guard rails which are adapted to be assembled together to form a rigid structure using appropriate connection assemblies.

[0004] The connection assemblies also comprise a plurality of support bearing hooks, which are vertically arranged along the uprights and are designed to fit into respective holes formed at the ends of the guard rails for removable fixation thereof to the uprights.

[0005] As the bearing hook is introduced, the end of the guard rail is caused to slide along the bearing hook to a locked position against the upright.

[0006] A first drawback of these arrangements is that the bearing hooks do not provide constant support to the guard rails, whereby they affect the rigidity of the entire structure.

[0007] US6006862 discloses a scaffolding structure which is similar to those as described above and has a plurality of vertically arranged support bearing hooks.

[0008] Particularly, each bearing hook has a substantially horizontal end portion that is rigidly joined to the upright, a pair of curved intermediate portions having opposite concavities and a slightly upwardly inclined free end portion, which is spaced from the upright with a predetermined clearance.

[0009] The free end portion is substantially horizontal and the guard rail comprises flat ends having respective holes, allowing them to be fitted on the bearing hook for removable fixation thereof.

[0010] Namely, each end hole must be aligned with the respective free end portion of the bearing hook before the latter is introduced therein, and for this purpose the end of the guard rail is placed in the space between the free end portion of the bearing hook and the upright in a substantially vertical position.

[0011] In this position, the edge of each end of the guard rail contacts the bearing hook portion that is rigidly joined to the upright, such that each hole is aligned with a respective free end portion.

[0012] Then, the guard rail end is caused to slide along the bearing hook to a locked position, level with the bearing hook portion that is rigidly joined to the upright.

[0013] A first drawback of this arrangement is that a very complex operation is required to place the ends of the guard rail in the space between the uprights and the bearing hook to facilitate alignment of the holes with the free end portions.

[0014] A further drawback is that the particular configuration of the intermediate portion, relative to the two horizontal end portions, does not facilitate the sliding movement of the hole along the bearing hook.

[0015] Another drawback is that the diameter of the end portion of the bearing hook that is rigidly joined to the upright is equal to the diameter of the free end portion, and larger than the diameter of the hole.

[0016] Thus, when the end of the guard rail is moved to the locked position, it can still slide along the end portion that is rigidly joined to the upright, which will affect the stability and rigidity of the entire structure.

Technical Problem

[0017] In view of the prior art, the technical problem addressed by the present invention consists in providing a connection assembly for connecting guard rails to uprights in a rigid scaffold, that can be very easily and quickly assembled and can impart constant rigidity to the scaffold over time.

Disclosure of the invention [0018] One object of the present invention is to obviate the above drawback, by providing a connection assembly for connecting guard rails to uprights of a rigid scaffold that is highly efficient and relatively cost-effective.

[0019] A particular object of the present invention is to provide a connection assembly as described above which allows a rigid scaffolding to be assembled in a very short time.

[0020] A further object of the present invention is to provide a connection assembly for connecting guard rails to uprights in a rigid scaffolding that simplifies the steps for alignment of the ends of the guard rails with their respective support bearing hooks.

[0021 ] Another object of the present invention is to provide a connection assembly as described above, that can ensure constant rigidity and stability of the scaffolding over time.

[0022] Yet another object of the present invention is to provide a connection assembly as described above that does not require particular assembly skills.

[0023] These and other objects, as more clearly explained hereafter, are fulfilled by a connection assembly for connecting guard rails to uprights in a rigid scaffolding as defined in claim 1 , comprising at least one guard rail for connecting uprights, which has free ends having respective through holes, and a plurality of support bearing hooks stably fixed to each upright of the scaffold at different heights in substantially equally spaced relationship. Each guard rail is designed to be connected to an upright by a bearing hook introduced into a respective end hole from an upper entry position to a lower connecting position.

[0024] In addition, each bearing hook comprises a lower end portion embedded in the upright with a substantially horizontal axis and an upper free end portion with a substantially vertical axis. Each hole is at a predetermined distance from the edge of its respective free end, which is equal to or slightly greater than the distance of the axis of the free end of the bearing hook from the outer surface of the upright to facilitate alignment of the hole with the bearing hook when the edge of the free end of the guard rail contacts its respective upright.

[0025] In a further aspect, the invention relates to a method of assembling a rigid scaffold comprising the aforementioned connection assembly, as defined in claim 10.

[0026] Advantageous embodiments of the invention are obtained in accordance with the dependent claims.

Brief description of the drawings

[0027] Further features and advantages of the invention will be more apparent from the detailed description of a preferred, non-exclusive embodiment of a connection assembly for connecting guard rails to uprights in a rigid scaffold, and a rigid scaffold according to the invention, which is described as a non-limiting example with the help of the annexed drawings, in which:

FIG. 1 is a front view, with a respective enlarged portion, of a rigid scaffold comprising the connection assembly of the invention;

FIG. 2 is a top view of a first detail of the connection assembly of Fig. 1 ; FIGS. 3 to 5 are perspective, front and side views respectively of a second detail of the connection assembly of Fig. 1 ;

FIGS. 6 to 8 are side and perspective views of successive assembly steps for assembling the scaffold of Fig. 1 .

Detailed description of a preferred exemplary embodiment

[0028] Particularly referring to the figures, an assembly is shown, generally designated by numeral 1 , for connecting guard rails 2 to uprights in a rigid scaffolding 4.

[0029] By way of example, the scaffolding 4 as shown in FIG. 1 may comprise a plurality of uprights 3 and guard rails 2 and may be used as is well known in the field of building and construction.

[0030] The guard rails 2 for connecting the uprights 3 impart rigidity to the scaffolding 4 and act as protective elements for the operators during use of the scaffolding 4.

[0031] In a preferred embodiment of the invention, the connection assembly 1 comprises at least one guard rail 2 for connecting uprights 3, which has free ends 5 with respective through holes 6 and extends along a longitudinal axis I.

[0032] As best shown in FIG. 2, each guard rail 2 comprises a tubular central body 7, and its ends 5 have a flat shape with a pair of parallel faces 5' and an outer edge 8 composed of a pair of straight sections 9 joined together by a curved section 1 0.

[0033] Furthermore, the connection assembly 1 comprises a plurality of support bearing hooks 1 1 which are stably fixed to each upright 3 of the scaffolding 4 at different heights h and in substantially equally spaced positions.

[0034] Each guard rail 2 is designed to be connected to a respective upright 3 by a bearing hook 1 1 introduced into a respective end hole 6 from an upper entry position to a lower connecting position.

[0035] In addition, each guard rail 2 may be supported at its ends 5 by respective bearing hooks 1 1 of two distinct uprights 3, placed at equal heights h from the ground.

[0036] Alternatively, the ends 5 of the guard rail 2 may be supported by bearing hooks 1 1 located at different heights h, such that the guard rail 2 may act as a cross brace of the rigid scaffolding 4.

[0037] The uprights 3, the guard rails 2 and the bearing hooks 1 1 can be made of a metal material, e.g. iron or steel, and the bearing hooks 1 1 may be welded to their respective uprights 3 in vertically arranged positions.

[0038] In a peculiar aspect of the invention, each bearing hook 1 1 comprises a lower portion 1 2, which is embedded in its respective upright 3 with a substantially horizontal axis X and an upper free portion 1 3 with a substantially vertical axis Y.

[0039] Thus, the two portions 1 2, 1 3 are substantially perpendicular to each other and are connected together by a substantially semicircular intermediate portion 14.

[0040] As best shown in FIG. 5, the intermediate portion 14 may have an outer radius of curvature r of 32 mm and is adapted to allow the end 5 of the guard rail 2 to slide from the entry position to the connecting position as it fits with its hole 6 thereon.

[0041 ] The curved intermediate portion 14 comprises a first section 14a joined to the upper portion 1 3 that extends away from the upright 3 and a second portion 14b joined to the lower portion 1 2 that extends toward the upright 3.

[0042] The first 14A and second 14B sections define together a substantially semicircular profile which projects outwards from the upper portion 1 3 of the bearing hook 1 1 .

[0043] In an alternative embodiment, not shown, the intermediate portion 14 can comprise a broken line composed of two oblique sections which are joined to the upper free portion 13 and the horizontal portion 1 2 of the bearing hook 1 1 respectively.

[0044] Each hole 6 is at a predetermined distance di from the edge 8 of its respective end 5 of the guard rail 2, which is equal to or slightly smaller than the distance d∑ of the vertical axis Y of the upper free portion 1 3 of the bearing hook 1 1 from the outer surface of the upright 3.

[0045] Namely, the predetermined distance di corresponds to the distance of the longitudinal axis I extending through a hole 6 from one of the two straight sections 9 of the flat end 5 and is equal to 28 mm.

[0046] This facilitates alignment of each end hole 6 with its respective bearing hook 1 1 when the edge 8 of the end 5 of the guard rail 2, particularly one of its straight sections 9, contacts its respective upright 3.

[0047] Furthermore, the semicircular profile of the intermediate portion 14 is adapted to allow the guard rail 2 to rotate about its longitudinal axis I as it is fitted with its through hole 6 on the upper portion 13 of the bearing hook 1 1 .

[0048] As best shown in FIG. 6, when one of the two straight sections 9 of the flat end 5 contacts the upright 3, the hole 6 will be aligned with the upper free portion 1 3 of the bearing hook 1 1 to be fitted thereupon.

[0049] However, when the free end 5 of the guard rail 2 is slid along the intermediate portion 14 and rotated at the first 14A and second 14B sections, the corresponding straight section 9 of the edge 8 no longer contacts the upright 3.

[0050] Furthermore, the predetermined distance di corresponds to the length I of the lower portion 1 2 of the bearing hook 1 1 embedded in the upright 3 and may also be different from that indicated above, without departure from the scope of the present invention.

[0051 ] Also, the semicircular profile of the intermediate portion 14 is at a distance d3 that is greater than the distance d∑ of the axis Y of the upper portion 1 3 from the upright 3.

[0052] Advantageously, as best shown in FIGS. 3 and 5, the upper free portion 13 of each bearing hook 1 1 may have a substantially oval cross- sectional shape with a predetermined maximum dimension d ₄ .

[0053] This maximum dimension d ₄ corresponds to the major axis of the oval and is 1 6mm, whereas the minor axis is 1 3mm and the intermediate portion 14 of each bearing hook 1 1 may have a shape and a maximum dimension that are equal to those of the upper free portion 1 3.

[0054] In addition, as best shown in FIG. 4, the lower portion 1 2 of each bearing hook 1 1 has a substantially circular cross-sectional shape with a diameter d ₅ that is greater than the maximum dimension d ₄ of its respective free end portion 1 3.

[0055] Each end hole 6 of the guard rails 2 may have a diameter d6 of about 20 mm whereas the diameter d ₅ of each lower portion 1 2 of the bearing hooks 1 1 may be substantially 1 7 mm.

[0056] Thus, the end 5 of each guard rail 2 may freely slide along the upper free portion 1 3 and the intermediate portion 14 of each bearing hook 1 1 as it is fitted thereon with its hole 6.

[0057] Conversely, when the end 5 of each guard rail 2 comes to the lower portion 1 2 of the bearing hook 1 1 , whose diameter d ₄ is greater than those of the other portions, it is prevented from sliding and stably remains in the connected position. [0058] Of course, these dimensions may be also other than those listed above, as needed, without departure from the scope of the invention.

[0059] In a further aspect, the invention relates to a method of assembling a rigid scaffolding 4 comprising at least one connection assembly 1 , as described above.

[0060] The method comprises a step of a) providing a plurality of uprights 3 that can be secured to the ground in a vertical position and a step of b) providing a plurality of bearing hooks 1 1 each having a substantially horizontal lower portion 1 2 and an upper free portion 1 3 having a substantially vertical axis Y.

[0061 ] The two portions 1 2, 1 3 are substantially perpendicular to each other and are joined by a substantially curved intermediate portion 14, as best shown in FIG. 5, having the first 14A and second 14B sections as described above.

[0062] The next step is a step of c) securing the bearing hooks 1 1 to the uprights 3 at different heights h and in substantially equally spaced positions and a step of d) providing a plurality of guard rails 2 having respective longitudinal axes I and ends 5 with respective end holes 6 formed therein.

[0063] The method further comprises a step of e) aligning each end hole 6 of the guard rails 2 with the upper free portion 1 3 of a respective support bearing hook 1 1 , as shown in FIG. 6, and a step of f) sliding the end 5 of the guard rail 2 along the intermediate portion 14 of the bearing hook 1 1 , i.e. along the first outwardly curved section 14A and the second inwardly curved section 14A, relative to the upright 3, from an upper entry position, as shown in FIG. 7.

[0064] During the step e) the flat end 5 of the guard rail 2 is maintained above of the bearing hook 1 1 substantially perpendicular to the upright 3.

[0065] Furthermore, the edge 8 of the end 5, particularly its straight sections 9, is kept in contact with the outer surface of the upright 3 to facilitate introduction of the upper free portion 13 of the bearing hook 1 1 into the corresponding end hole 6. [0066] Moreover, during the step of f) sliding along the intermediate portion 14, the end 15 of each guard rail 2 is rotated about its longitudinal axis I first in one direction, at the first section 14A, and then in the opposite direction, at the second section 14B, such that it will contact the upright 3.

[0067] The final step is a step of g) placing the end 5 of the guard rail in a stable connected position at the lower horizontal portion 12 of bearing hook 1 1 , as shown in FIG. 8.

[0068] In this position, the end 5 of the guard rail 2 is locked substantially parallel to the upright 3, with one of the two faces 5' contacting it.

[0069] It will be appreciated from the foregoing that the connection assembly and the assembly method of the invention fulfill the intended objects and particularly can afford very simple and quick assembly of a rigid scaffold.

[0070] The connection assembly and the assembly method of the invention are susceptible to a number of changes or variants, within the inventive concept disclosed in the appended claims.

[0071 ] While the connection assembly and the assembly method have been described with particular reference to the accompanying figures, the numerals referred to in the disclosure and claims are only used for the sake of a better intelligibility of the invention and shall not be intended to limit the claimed scope in any manner.

Industrial Applicability

[0072] The present invention may find application in industry, because it can be produced on an industrial scale by construction scaffolding manufacturers.