Scaffold and frame for scaffold

Abstract

A scaffold, an end frame assembly for a scaffold and a method for manufacturing an end frame for a scaffold. The scaffold includes a platform configured for supporting a user of the scaffold. The scaffold also includes a frame for supporting the platform. The frame includes a pair of end frames. Each end frame in the pair of end frames includes a pair of legs. Each leg of the pair of legs includes an elongated body made of a composite material. The elongated body has an exterior surface and an interior surface spaced from the exterior surface. The interior surface defines a hollow interior cavity extending along an extent of the elongated body. At a specific cross-section taken transversely to the extent of the body, a distance between the exterior surface and the interior surface varies about a periphery of the hollow interior cavity.

Description

CROSS-REFERENCE TO RELATED APPLICATION

[0001] The present application claims the benefit of priority under 35 U.S.C. 119 based on U.S. provisional application No. 63 / 762,525 filed on Feb. 24, 2025. The contents of the aforementioned application are incorporated herein by reference.TECHNICAL FIELD

[0002] The subject matter disclosed generally relates to scaffolds. More particularly, the subject matter disclosed relates to a frame for a scaffold, for example a Baker type scaffold.BACKGROUND

[0003] Mobile scaffolds have been used in the constructions industry for many years. Such mobile scaffolds may be used in interior and exterior situations to provide access for tasks that do not justify the use of fixed scaffolds. Typically, known mobile scaffolds include a platform for supporting a worker and a frame for supporting the platform, the frame including end frames and side braces.

[0004] The frame of a mobile scaffold is typically made of metal (e.g., steel or aluminum) for providing strength and durability to the frame.

[0005] However, while metal framed scaffolds offer benefits, they also present several significant drawbacks that can compromise safety, efficiency, and usability in various working conditions.

[0006] For instance, once such drawback is that scaffolds having steel frames can be heavy, which can have several downsides in terms of manoeuvrability, making it difficult to setup and reposition the scaffold during a construction job. Additionally, the weight of steel frames can make the transport of scaffolds cumbersome and can increase related transportation costs due to higher fuel consumption of vehicles or vessels carrying such scaffolds.

[0007] Instead of steel, the frames of a scaffold may instead be made with aluminum.

[0008] While aluminum frames seek to mitigate some of the weight-related disadvantages associated with steel frames, they can have other downsides, such as being prone to deformation under high loads.

[0009] Electroconductivity is yet another downside of metal frames, such as steel and aluminum scaffold frames, which makes such scaffolds unsuitable for certain work environments where workers may be near electrical powerlines / cables as such metal frames may present a serious electrical hazard.

[0010] Additionally, components of a metal frame (e.g., rails, steps etc. . . . ) are typically welded to one another, which renders it difficult to repair parts of the frame without replacing the entire frame if it is damaged, thus potentially reducing the usable lifespan of the metal frame.

[0011] Other downsides also include corrosion, heat retention, high manufacturing costs, etc., which may also be drawbacks of scaffolds with metal frames.

[0012] In view of the above, it is apparent that there is need for improved scaffold frames that alleviate at least in part some of the above identified deficiencies.SUMMARY

[0013] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This summary is not intended to identify all key aspects and / or essential aspects of the invention.

[0014] In accordance with various aspects of this disclosure, there is provided a scaffold, an end frame assembly for a scaffold and a method for manufacturing an end frame assembly for a scaffold.

[0015] For instance, in accordance with an aspect of the disclosure, there is provided a scaffold comprising a platform configured for supporting a user of the scaffold. The scaffold also comprises a frame for supporting the platform. The frame comprises a pair of end frames. Each end frame in the pair of end frames comprises a pair of legs. Each leg of the pair of legs is comprised of an elongated body made of a composite material. The elongated body has an exterior surface and an interior surface spaced from the exterior surface. The interior surface defines a hollow interior cavity extending along an extent of the elongated body. At a specific cross-section taken transversely to the extent of the body, a distance between the exterior surface and the interior surface varies about a periphery of the hollow interior cavity.

[0016] In some specific implementations, at the specific cross-section, the hollow interior cavity may define a constant radius.

[0017] In some specific implementations, at the specific cross-section, the hollow interior cavity may define a circular shape.

[0018] In some specific implementations, at the specific cross-section, the hollow interior cavity may define a polygonal cross-sectional shape comprising five or more sides.

[0019] In some specific implementations, the interior surface may be comprised of reinforcing portions disposed within the elongated body.

[0020] In some specific implementations, the elongated body may be an elevated rectangular body.

[0021] In some specific implementations, at the specific cross-section, the exterior surface of the elongated body may form a rectangular shape.

[0022] In some specific implementations, at the specific cross-section, the exterior surface of the elongated body may form a square shape.

[0023] In some specific implementations, at any cross-section taken transversely to the extent of the elongated body, the distance between the exterior surface and the interior surface may vary about the periphery of the hollow interior cavity.

[0024] In some specific implementations, the elongated body may be constructed by a pultrusion process.

[0025] In some specific implementations, the composite material may comprise a fiberglass reinforced polymer material or aramid reinforced polymer material.

[0026] In some specific implementations, a load-to-weight ratio of the scaffold may be greater than 7.5.

[0027] In some specific implementations, a load-to-weight ratio of the scaffold may be about 8.

[0028] In some specific implementations, the scaffold further may comprise one or more rungs extending between the pair of legs.

[0029] In some specific implementations, a material of the one or more rungs me be different from the composite material of the body. For example, the material of the one or more rungs may comprise aluminum and / or steel.

[0030] In some specific implementations, the one or more rungs may be connected to the pair of legs at a weld-free connection.

[0031] In some specific implementations, the frame may comprise a plurality of connectors for connecting the one or more rungs to the pair of legs.

[0032] In some specific implementations, the plurality of connectors may include one or more brackets.

[0033] In accordance with another aspect of the disclosure, there is provided an end frame for a scaffold. The end frame comprises a pair of legs. Each leg of the pair of legs is comprised of an elongated body made of a composite material. The elongated body has an exterior surface and an interior surface spaced from the exterior surface. The interior surface defines a hollow interior cavity extending along an extent of the body. At a specific cross-section taken transversely to the extent of the body, a distance between the exterior surface and the interior surface varies about a periphery of the hollow interior cavity. The end frame further comprises one or more rungs extending between the pair of legs.

[0034] In accordance with another aspect of the disclosure, there is provided a method of manufacturing an end frame for a scaffold. The method comprises the step of forming a pair of legs by pultrusion of a composite material. Each leg of the pair of legs comprises an elongated body having an exterior surface and an interior surface spaced from the exterior surface. The interior surface defines a hollow interior cavity extending along an extent of the elongated body. At a specific cross-section taken transversely to the extent of the body, a distance between the exterior surface and the interior surface varies about a periphery of the hollow interior cavity. The method also comprises the step of coupling one or more horizontal rungs to the pair of legs.

[0035] All features of exemplary embodiments which are described in this disclosure and are not mutually exclusive can be combined with one another. Elements of one embodiment or aspect can be utilized in the other embodiments / aspects without further mention.

[0036] These and other aspects of this disclosure will now become apparent to those of ordinary skill in the art upon review of a description of embodiments that follows in conjunction with accompanying drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The above-mentioned features and objects of the present disclosure will become more apparent with reference to the following description taken in conjunction with the accompanying drawings, wherein like reference numerals denote like elements and in which:

[0038] FIG. 1A is a prior art scaffold;

[0039] FIG. 1B is a leg of the prior art scaffold of FIG. 1A;

[0040] FIG. 1C is a cross-sectional view of a leg of the prior art scaffold of FIG. 1B taken along line C-C; and

[0041] FIG. 2A is a perspective view of a scaffold including a frame, in accordance with an embodiment of the present disclosure;

[0042] FIG. 2B is an exploded view of the scaffold of FIG. 2A;

[0043] FIG. 3 is a right elevation view of an end frame of the scaffold of FIG. 2A;

[0044] FIG. 4 is an enlarged front elevation view of a side rail locking mechanism of the scaffold of FIG. 2A;

[0045] FIG. 5A is a perspective view of a leg of the end frame of the scaffold of FIG. 2A including a scaffold connector and a caster;

[0046] FIG. 5B is a rear elevation view of the leg of FIG. 5A;

[0047] FIG. 6 is a left elevation view of the leg of FIG. 5A;

[0048] FIG. 7 is a section view of the leg of FIG. 6 taken along line A-A;

[0049] FIG. 8 is a section view of a scaffold connector of the leg of FIG. 6;

[0050] FIG. 9 is a section view of a caster of the leg of FIG. 6;

[0051] FIG. 10 is a cross-sectional view of the leg of FIG. 6 taken along line B-B, in accordance with a specific example;

[0052] FIG. 11 is the cross-sectional view of the leg of FIG. 10 showing reinforcing portions of the leg;

[0053] FIGS. 12A to 12F are cross-sectional views of the leg of FIG. 6 along line B-B, in accordance with various alternative embodiments;

[0054] FIG. 13A is an enlarged perspective view of a connector for horizontal rungs of the frame of the scaffold of FIG. 2A, in accordance with a specific example;

[0055] FIG. 13B is an enlarged perspective view of a connector for horizontal rungs of the frame of the scaffold of FIG. 2A, in accordance with another specific example;

[0056] FIG. 14 is a perspective view of a scaffold assembly including a guard rail, in accordance with an alternative embodiment of the disclosure;

[0057] FIG. 15 shows a flow diagram of a method of manufacturing a side rail assembly for a scaffold of the type depicted in FIG. 2A, in accordance with a specific embodiment; and

[0058] FIG. 16 is a schematic illustrating an specific pultrusion process for manufacturing a leg of the end frame of the scaffold of FIG. 2A.

[0059] In the drawings, embodiments are illustrated by way of example. It is to be expressly understood that the description and drawings are only for purposes of illustrating certain embodiments and are an aid for understanding. They are not intended to be a definition of the limits of the invention.DETAILED DESCRIPTION OF EMBODIMENTS

[0060] A detailed description of one or more specific embodiments of the invention is provided below along with accompanying Figures that illustrate principles of the invention. The invention is described in connection with such embodiments, but the invention is not limited to any specific embodiment. It is to be appreciated that the embodiments described are being provided only for the purpose of illustrating the inventive principles and should not be considered as limiting. The scope of the invention is limited only by the claims. Numerous specific details are set forth in the following description in order to provide a thorough understanding of the invention. These details are provided for the purpose of describing non-limiting examples and the invention may be practiced according to the claims without some or all of these specific details. For the purpose of clarity, technical material that is known in the technical fields related to the invention has not been described in great detail so that the invention is not unnecessarily obscured.

[0061] FIGS. 2A, 2B and 3 show a scaffold assembly 2 comprising a mobile scaffold 10 in accordance with an embodiment of the present disclosure. The scaffold 10 comprises a platform 88 and a frame 11 for supporting the one or more platforms 88. The frame 11 includes a set of end frame assemblies 12 (also referred to as “end frames”) and a set of side rail assemblies 46. The scaffold 10 includes a longitudinal direction, a vertical direction and a transverse direction transverse to the longitudinal and the vertical directions. The longitudinal, vertical and transverse directions are respectively denoted X, Y and Z, as shown in FIG. 2A.

[0062] In one embodiment, the scaffold assembly 2 includes a single mobile scaffold 10. In other embodiments (not shown in the figures), the scaffold assembly 2 may include a plurality of mobile scaffolds 10 stackable in the vertical direction (Y).

[0063] The platform 88 is configured for supporting a user of the scaffold 10. The platform 88 includes a body 91 comprising an upper surface 90 and a lower surface 92 and a thickness 102 defined between the upper and lower surfaces 90, 92. The body 91 includes a first end 87 and a second end 89 opposite the first end 87. The body 91 includes a first lateral edge 83 and a second lateral edge 85 opposite the first lateral edge 83 in the transverse direction (Z). The body 91 of the platform 88 includes a periphery 94. The platform 88 may be configured in any suitable fashion. In some embodiments, the platform 88 may include a frame 98 disposed about at least a portion (e.g., a portion or an entirety) of the periphery 94 of the platform 88. A height of the platform 88 is adjustable in the vertical direction (Y) of the scaffold 10. For instance, the platform 88 may be adjustable between a minimum height and a maximum height. The platform 88 may have any suitable shape and dimensions. The platform 88 (e.g., the body 91 and / or the frame 98) may be comprised of any suitable material or combination of materials, including, for example, metals (steel, iron, aluminum, etc.), wood, plastic etc. In some embodiments, the platform 88 may include a trap door 104 operable to provide access to the platform 88 and / or the end frame assemblies 12 (e.g., an end frame assembly 12 of a scaffold 10 stacked above or below a given scaffold 10). In some embodiments, the platform 88 may include one or more apertures 106 to facilitate handling (e.g., grabbing, moving, installing, transporting, etc.) of the platform 88.

[0064] With further reference to FIGS. 2A and 2B, the frame 11 of the scaffold 10 includes two end frame assemblies 12 configured for coupling with the side rail assemblies 46 and for supporting the platform 88. With reference to FIGS. 2A, 2B and 3, each end frame assembly 12 includes a ladder 14 including a pair of legs 16 (e.g., left and right legs) and one or more rungs 26 extending between the pair of legs 16. The rungs 26 extend transversely between the pair of legs 16 so as to be substantially horizontal when the pair of legs 16 are positioned upright when in an “in-use” configuration. The ladder 14 is configured for allowing the user to climb the scaffold 10 (e.g., to reach a given one of the platforms 88).

[0065] With reference to FIGS. 5A and 5B, each leg 16 includes a first end 20 and a second end 22 opposite the first end 20 along a longitudinal direction L16 of the leg 16. Each leg 16 comprises a body 18 comprising an exterior surface 33. The body 18 extends along the longitudinal direction L16 of the leg 16. In this way, the body 18 is an elongated body (and will be referred to as such going forward). An extent of the elongated body 18 is defined along the longitudinal direction L16 of the leg 16.

[0066] The elongated body 18 may be configured in any suitable fashion and may have any suitable shape, material and dimensions. For instance, the elongated body 18 may be comprised of a material 29 which may include, for example, metals (steel, iron, aluminum, etc.), composite materials, amongst others. In one embodiment, the elongated body 18 may be comprised of a substantially (e.g., majoritarily, etc.) solid member. In other embodiments, the elongated body 18 may be tubular so that an inner portion may be at least partially hollow. In a specific embodiment, the elongated body 18 may include an interior surface 31 spaced from the exterior surface 33. The interior surface 31 of the elongated body 18 defines a hollow interior cavity 37 having a periphery 13. The hollow interior cavity 37 may be continuous within the elongated body 18 and may extend along the extent of the elongated body 18. The exterior and interior surfaces 33, 31 define a wall 41 of the elongated body 18. In some alternative implementations, not shown in the figures, the elongated body 18 may include a plurality of hollow interior cavities 37 arranged along the extent of the elongated body 18, wherein the hollow interior cavities 37 are interleaved with solid portions. Such interleaved solid portions impart added strength and rigidity to the elongated body.

[0067] With reference to FIGS. 6 and 10, there is shown a specific cross-section XSi taken transversely to the extent of the elongated body 18. As is illustrated in FIG. 10, the exterior surface 33 forms an exterior cross-sectional shape 15 of the elongated body 18. The elongated body 18 may include any suitable exterior cross-sectional shape 15 (e.g., rectangular, square, circular, polygonal, elliptical, etc.) and may have any suitable exterior cross-sectional dimensions. For instance, the elongated body 18 may be an elevated rectangular body (i.e., the elongated body 18 is an elevated body comprising an exterior cross-sectional shape 15 substantially forming a rectangle). In a specific non-limiting example, the elongated body 18 may have an exterior cross-sectional shape 15 forming a square which may have sides with dimensions between 1 inch and 2 inches.

[0068] In some embodiments, the elongated body 18 may include one or more openings 24 along at least a portion of the extent of the body 18 which are engageable by a releasable locking mechanism 74 to couple the side rail assemblies 46 to the ladders 14 so that the platform 88 may be set at a desired height along the elongated body 18 of the legs 16 of the ladders 14. In specific embodiments, the one or more openings 24 may include a plurality of openings arranged along the extent of the body 18. The openings in the plurality of openings may be arranged in an equidistant manner relative to one another along the extent of the body 18 or may be arranged in a non-equidistant manner depending on the desired heights along the elongated body 18 that the platform 88 may be set. The spacing between openings may vary between implementations. In specific implementations, the distance tends to range between 1 inches and 2 inches.

[0069] With further reference to FIG. 3, each rung 26 includes a first end 30 and a second end 32 opposite the first end 30. The rungs 26 may be configured in any suitable fashion and may have any suitable shape and dimensions and may be made in any suitable material or combination of materials. Each rung 26 comprises a body 28. In one embodiment, the body 28 of the one or more of the rungs 26 may be formed as a substantially (e.g., partially, majoritarily, etc.) solid member. In other embodiments, the body 28 of the one or more of the rungs 26 may be formed as a tubular body so that an inner portion of the body may be at least partially hollow. The rungs 26 may include any suitable exterior or interior cross-sectional shape (e.g., rectangular, square, circular, polygonal, elliptical, etc.) and any suitable exterior or interior cross-sectional dimensions. The rungs 26 may be formed using materials including, for example, metals (steel, iron, aluminum, etc.), plastics and / or plastic composites.

[0070] The end frame assembly 12 may further include ground-engaging members 35 configured to be coupled to the one or more legs 16 at the second end 22 of the one or more legs 16. For instance, at least some of the legs 16 may be mounted on ground-engaging members 35. For example, each leg 16 may be mounted on ground-engaging members 35. Different types of ground-engaging members 35 may be contemplated in practical implementations. In one example, the ground-engaging members 35 may include base plates (not shown in the figure). In another example, the ground-engaging members 35 may include casters 36 to provide added mobility to the scaffold 10. For instance, at least some of the legs 16 may be mounted on casters 36. For example, in this case, each leg 16 is mounted on a caster 36. The casters 36 may be configured in any suitable fashion and may have any suitable shape, material and dimensions. Some or all of the casters 36 may be configured with wheel locking mechanisms to prevent motion of caster wheels, and thereby prevent motion of the scaffold 10, while the scaffold 10 is installed for use.

[0071] With reference to FIG. 9, the caster 36 include a wheel 42 and a stem 38 for mounting the casters 36 to the legs 16. The stem 38 is configured to matingly engage a portion of the hollow interior cavity 37 defined by the elongated body 18 of the leg 16 at the second end 22 of the leg 16. In this example, the end frame assembly 12 further includes locking pins 44 to lock the casters 36 with respect to the legs 16. For instance, the stem 38 includes an opening 40 to receive the locking pin 44 which is configured to extend through the opening 40 in the stem 38 of the caster 36 and through a given opening 24 in the leg 16 to fasten the caster 36 to the leg 16.

[0072] With reference to FIG. 8, in some specific embodiments, each leg 16 includes a scaffold connector 59 disposed at the first end 20 of the leg 16. The scaffold connector 59 is configured for facilitating stacking of multiple scaffolds 10 atop one another in a vertical direction Y. The scaffold connector 59 may be configured in any suitable fashion and may have any suitable shape, material and dimensions. In one example, the scaffold connector 59 is a pin connector 61. The pin connector 61 at the first end 20 of a given leg 16 of a first scaffold 10 is configured to engage, and be at least partially disposed within, the second end 22 of a corresponding leg 16 of a second scaffold 10 stacked atop the first scaffold 10 in the vertical direction Y. For example, the pin connector 61 at the first end 20 of a given leg 16 of a first scaffold 10 is configured to engage, and be at least partially disposed within, the hollow cavity 37 of the body 18 of a corresponding leg 16 of a second scaffold 10 stacked atop the first scaffold 10 in the vertical direction Y. In a non-limiting implementation, the pin connector 61 may be a cylindrical pin connector 61. In another example, the pin connector 61 may comprise any suitable exterior or interior cross-sectional shape (e.g., rectangular, square, circular, elliptical, etc.) and may have any suitable exterior or interior cross-sectional dimensions. The scaffold connector 59 may be made of a material including, for example, metals (steel, iron, aluminum, etc.), plastics, plastic composites, etc. The scaffold connector 59 may be coupled to the leg 16 in any suitable fashion, including through the use of mechanical fasteners, by metal joining (e.g., welding, brazing, soldering, etc.), by adhesives, etc.

[0073] In some alternative embodiments, the scaffold assembly 2 may include a guard rail 108 as shown in FIG. 14. The guard rail 108 may be configured in any suitable fashion and may have any suitable shape and dimensions and may be made of any suitable material or combination of materials. For instance, in some embodiments, the guard rail 18 may have a substantially cylindrical cross section with a diameter between 1 inch or 1.5 inches. In alternative specific examples, not shown in the Figures, the guardrail 18 may have a substantially elliptical or polygonal cross section and the cross section may be of any suitable dimension.

[0074] With further reference to FIGS. 2A and 2B, the scaffold 10 includes two side rail assemblies 46 including side rails 48 that extend longitudinally between elevated end frame assemblies 12 along the lateral edges 85, 83 of the platform 88 to support the platform 88.

[0075] Each side rail 48 includes a first end 51, a second end 53 opposite the first end 51, a top edge 56, a bottom edge 58 opposite the top edge 56, an outer surface 50 and an inner surface 52 opposite the outer surface 50. The side rail 48 extends along a longitudinal direction, a vertical direction and a transverse direction which generally coincide with the longitudinal direction (X), the vertical direction (Y) and the transverse direction (Z) of the scaffold 10 when the side rail 48 is mounted to the scaffold 10. A height H48 of the side rail 48 is defined between the top edge 56 and the bottom edge 58 of the side rail 48. The side rail 48 may be configured in any suitable fashion and may have any suitable shape and dimensions and made be made with any suitable material or combination of materials. For instance, the side rail 48 may be made, for example, of a metallic material (steel, iron, aluminum, etc.), or of a composite material (a reinforced plastic, such as a fiber reinforced polymer matrix composite, e.g., a fiberglass composite, a carbon-fiber reinforced composite, an aramid reinforced-composite, etc.), or any other suitable material.

[0076] In some embodiments, the inner surface 52 of the side rail 48 includes a platform support 54. In one example, the platform support 54 is configured as a platform supporting surface 55 upon which the platform88 is configured to be disposed and sit. With reference to FIG. 2B, in one specific example, the platform supporting surface 55 comprises a ledge upon which a lateral edge 83, 85 of the platform 88 may be supported. In some cases, at least a portion of the lower surface 92 of the platform 88 may be disposed on the platform supporting surface 55 when the side rail 48 supports the platform 88. To assist in locating the platform 88 onto the side rails 48, one or more of the side rails 48 may include a locking projection 60 configured to be inserted into a corresponding locating recess 96 on the platform 88. In one example of implementation, the locating projection 60 of the side rail 48 includes a pin 64 and the locating recess 96 on the platform 88 includes a hole. In one non-limiting example, the pin 64 may be configured to be mechanically attached or coupled to the side rail 48. In other non-limiting examples, the pin 64 and the side rail 48 may be a unitary construction (e.g., the pin 64 and the side rail 48 may be integral with one another). In one non-limiting example, the locating recess 96 of the platform 88 may be adjacent to or at the periphery 94 of the platform 88. In some implementations, the locating recess 96 may extend at least partly, or fully, through the frame 98 of the platform 88.

[0077] The side rail assemblies 46 are configured to be fastened to the end frame assemblies 12. The side rail assemblies 46 may be fastened to the end frame assemblies 12 in any suitable fashion. In one embodiment, each side rail assembly 46 includes a connector 65 for connecting the side rail 48 to the ladder 14. In one example of implementation, the connector 65 comprises a channel 66 disposed at an end 51, 53 of the side rail 48 for coupling the side rail assembly 46 to the end frame assemblies 12. In this embodiment, the channel 66 is configured to be disposed about at least a portion of the legs 16 of the ladders 14. In the specific example depicted, the channels 66 are configured as C-shaped channels configured to slidingly engage the exterior surface 33 of the elongated body 18 of the legs 16 of the ladders 14 of the end frame assemblies 12 to adjust the height of the platform 88. Each channel 66 may be releasably locked relative to the ladder 14 for locking the platform 88 at a desired height. While the specific embodiment depicted in the drawings shows channels 66 configured as C-shaped channels, it will be appreciated that other suitable configurations are possible. In specific practical examples, the configuration of the channels 66 may be complementary to the configuration of the exterior surface 33 of the body 18 of the legs 16 of the ladders 14 to permit the channels 66 to slidingly engage the exterior surface 33 of the body 18 of the legs 16.

[0078] In specific embodiments, as shown in FIG. 4, one or more side rail locking mechanisms 74 may be provided to releasably lock the side rails 48 into place a specific desired height along the extent of the elongated body 18 of the legs 16. In a specific example of implementation, the side rail locking mechanism 74 includes a locking pin 78 that engages with openings 24 along the extent of the elongated body 18 of the legs 16 and openings 70 in the channel member 66 respectively to lock the side rail 48 at a desired height. When the platform 88 is adjusted to the desired height, ends 86 of the locking pin 78 can be inserted through the openings 70 in the channel 66 and the openings 24 in the legs 16 that align with the openings 70 in the channel 66. In one example of implementation, the locking pin 78 is a U-shaped locking pin and comprises a handle 76. In this example, the locking pin 78 is biased in an engaged position by springs 82. In operation, to adjust the height of the platform, the locking pin 78 is pulled back by the handle 76 against a L-shaped frame 84 to disengage the locking pin 78 from the holes 24 in the legs 16. Once disengaged, the platform 88 can be adjusted in height to a desired position by sliding the connector 65 along the longitudinal extent of the ladder 14.

[0079] With further reference to FIG. 4, in one embodiment, the side rail assembly 46 may include a latching mechanism 23 to restrict motion of the platform 88 relative to the side rail assembly 46. In one embodiment, the latching mechanism 23 comprises a pin 1013 including a stem 1017, a tab 1011 and a biasing member 1019 to bias the pin 1013 into engagement with the platform 88, as shown in FIG. 2A. In FIG. 2A, the locking tab 1011 is shown in an engaged position and overlaps at least a portion of the platform 88 and at least a portion of the top edge 56 of the side rail 48. The pin 1013 may also be actuated to adopt a disengaged position, so as to not engage the platform 88 such that the tab 1011 no longer overlaps any portion of the platform 88. In order to change the position of the pin 1013 from the engaged position shown in FIG. 2A to the disengaged position (not shown), a user may displace the latching mechanism 23 upwards by pulling on the latching mechanism 23 (e.g., pulling upward on the locking tab 1011) or pushing on the stem 1017 and rotating the pin 1013 so as to adopt the disengaged position. The configuration and operation of latching mechanisms of the type depicted in FIG. 4 are known in the art and are beyond the scope of the present disclosure and thus will not be described in further detail here.

[0080] In one embodiment, parts of the frame 11 of the scaffold 10 are configured for improved performance (e.g., capability, maneuverability, safety, etc.), construction (e.g., manufacturing), servicing (e.g., repair, maintenance, etc.) of the scaffold 10. For example, in one embodiment, one or more of the end frame assemblies 12 may be configured for improved performance, construction and servicing of the scaffold 10.

[0081] For instance, the end frame assembly 12 may be configured for improved capability by improving a load-to-weight ratio of the overall scaffold 10 (also known as “strength-to-weight ratio” or “specific strength”, which is a measure of how much load a scaffold can bear relative to its weight or mass) as compared to some conventional scaffolds.

[0082] In particular, in some embodiments, the elongated body 18 may be configured so as to provide an improved load-to weight ratio of the scaffold 10 relative to conventional scaffolds with legs with hollow bodies. Such improved load-to weight ratio may be achieved, at least in part, based on a configuration of the cross-section of the leg 16 and / or the material 29 of the body 18 of the leg 16, as will be described further below.

[0083] FIGS. 1A, 1B and 1C shows a conventional scaffold 2000 including a frame 2005. The frame 2005 includes an end frame assembly 2007 comprising a pair of legs 2009. A given leg 2009 includes an elongated body 2011 having an extent defined in a longitudinal direction L2009 of the leg 2009. FIG. 1C shows a cross-section PXSi of the body 2011 taken transversely to the extent of the elongated body 2000 as shown in FIG. 1B. The body 2011 may be made of a metallic material (e.g., steel, aluminum) such that the scaffold 2000 is a metal framed scaffold. The body 2011 includes an interior surface 2015 spaced from an exterior surface 2013. The interior surface 2015 of the body 2011 defines a hollow interior cavity 2017 having a periphery 2018. The hollow interior cavity 2017 extends along the extent of the body 2011 in the longitudinal direction L2009 of the leg 2009.

[0084] Conventional scaffolds (e.g., such as the scaffold of FIG. 1A) may weigh between 60 pounds (lb.) and 170 lb. (27 kilograms (kg) and 77 kg) and may support loads between 700 lb. and 1500 lb. (317 kg and 680 kg), and typically have a load-to-weight ratio ranging between 7 to 10.

[0085] In one example of implementation for the scaffold contemplated by the present disclosure, the elongated body 18 of the legs 16 of the scaffold 10 is configured such that the load-to-weight ratio of the scaffold 10 is in some cases greater than 7.5, in some cases greater than 7.96, in some cases greater than 8, in some cases greater than 10, in some cases greater than 10.5, in some cases greater than 11, in some cases greater than 11.5, in some cases greater than 12, and in some cases even greater. In some cases, the load-to-weight ratio of the scaffold 10 is about 8.

[0086] In one embodiment, the elongated body 18 of the legs 16 of the scaffold 10 may be tubular and is made of a material, and has a specific configuration, that imparts and improved load-to-weight ratio. More specifically, the material 29 of the elongated body 18 may be a composite material 27 (e.g., a reinforced plastic, such as a fiber reinforced polymer matrix composite, e.g., a fiberglass composite, a carbon-fiber reinforced composite, an aramid reinforced-composite, etc.). Such composite material typically have a lower weight per volume than metallic materials, which may result in a scaffold having an overall lighter weight than a conventional metallic scaffold. For example, steel may have a density ranging from approximately 7.75 g / cm3 to 8.05 g / cm3, iron may have a density ranging from approximately 7.85 g / cm3 to 7.87 g / cm3 and aluminum may have a density ranging from approximately 2.64 g / cm3 to 2.81 g / cm3. In contrast, fiberglass composite may have a density ranging from approximately 1.5 g / cm3 to 2.7 g / cm3, carbon-fiber reinforced composite may have a density ranging from approximately 1.55 g / cm3 to 1.8 g / cm3, an aramid reinforced-composite may have a density ranging from approximately 1.30 g / cm3 to 1.47 g / cm3. By configuring the body 18 to be made with the composite material 27, the scaffold 10 may have a greater load capacity while having a lower overall weight than as compared to a prior art scaffold (e.g., scaffold 2000 shown in FIG. 1A) comprising a metallic material (e.g., steel, iron, aluminum, etc.) given the strength-to-weight ratio of the composite material 27.

[0087] Moreover, the lower overall weight of the scaffold 10 may improve the maneuverability of the scaffold 10 (e.g., by facilitating moving or otherwise displacing the scaffold 10 on a worksite, moving or otherwise displacing the scaffold 10 to and / or from a location other than a worksite (e.g., over a range of distances (e.g., long, short), and / or by a range of methods (e.g., manually, by vehicle, by vessel, etc.), reducing transportation costs, and reducing the risk of physical injury due to manipulating heaving equipment, etc.

[0088] Furthermore, by configuring the body 18 to be made with the composite material 27, since composite material have materially lower conductivity than metals, the safety of the scaffold 10 may be improved by mitigating electrical hazard risks as compared to metal-framed scaffolds given the limited electroconductivity (e.g., reduced electroconductivity or non-electroconductivity) of the composite material 27.

[0089] In one embodiment, which will be described in part with reference to FIG. 10, the elongated body 18 is configured such that at a specific cross-section XSi taken transversely to the extent of the body 18, a distance ti between the exterior surface 33 and the interior surface 31 varies about a periphery 13 of the hollow interior cavity 37. In one embodiment, at any cross-section XS1-XSn taken transversely to the extent of the elongated body 18, the distance ti between the exterior surface 33 and the interior surface 31 varies about the periphery 13 of the hollow interior cavity 37. The distance ti is a distance measured along a normal Ni (i.e., a perpendicular distance) extending between the exterior and interior surfaces 33, 31 at a given point Pi along the periphery 13 of the hollow interior cavity 37. This distance ti may be referred to as a peripheral thickness ti. Thus, at the specific cross-section XSi taken transversely to the extent of the body 18, the peripheral thickness ti of the body 18 is variable so that the peripheral thickness is greater is some locations than in others about the periphery 13 of the hollow interior cavity 37. In one example of implementation, the peripheral thickness ti of the body 18 is variable along a portion of the periphery 13 of the hollow interior cavity 37. In one example of implementation, the peripheral thickness ti of the body 18 is variable along a majority of the periphery 13 of the hollow interior cavity 37. In one example of implementation, the peripheral thickness ti of the body 18 is variable along an entirety of the periphery 13 of the hollow interior cavity 37.

[0090] For instance, as shown in FIG. 10, a peripheral thickness t3 taken along normal N3 at point P3 along the periphery 13 of the hollow interior cavity 37 is different from a peripheral thickness t2 taken along normal N2 at point P2 along the periphery 13 of the hollow interior cavity 37. In a further example, the peripheral thicknesses t3, t2 are also different from a peripheral thickness t1 taken along normal N1 at point P1 along the periphery 13 of the hollow interior cavity 37. In the specific example shown in FIG. 10 where the exterior cross-sectional shape 15 of the body 18 is substantially square and the peripheral thickness ti of the body 18 increases as one nears the corners of the square (e.g., peripheral thickness near P3 is greater than the peripheral thickness near P1).

[0091] With reference to FIG. 11, by configuring the peripheral thickness ti of the body 18 to be variable, certain portions 112 of the wall 41 of the body 18 (e.g., as denoted as dotted regions of the wall 41 in FIG. 11) are reinforced so as to allow the scaffold 10 to have a greater load capacity than if the elongated body 18 was configured without said portions 112 of the wall 41 being reinforced. In this way, the portions 112 can be considered to be reinforcing portions 112 disposed within the elongated body 18 such that part of the interior surface 31 is comprised of reinforcing portions 112.

[0092] In contrast, with reference to FIG. 1C showing the cross-section of the the prior art scaffold 2000, it is noted that a peripheral thickness ti of the body 2011 is not variable but rather is substantially constant. For instance, a peripheral thickness t4 taken along normal N4 at point P4 along the periphery 2018 of the hollow interior cavity 2017 is the same as a peripheral thickness t5 taken along normal N5 at point P5 along the periphery 2018 of the hollow interior cavity 2017. It is also noted that the interior surface 2015 of the body 2011 in the prior art scaffold 2000 does not include reinforcing portions (e.g., such as reinforcing portions 112 of the body 18 of the scaffold 10 presented in the present disclosure).

[0093] In specific examples of implementation, at the specific cross-section XSi, the hollow interior cavity 37 of the body 18 defines a constant radius R. At a specific cross-section XSi of the elongated body 18 taken transversely to the extent of the elongated body 18, the interior surface 31 defines a shape 43. In one example of implementation, at the specific cross-section XSi, the hollow interior cavity 37 of the body 18 defines a circular shape such that the shape 43 is a circle. In an alternative example of implementation, at the specific cross-section XSi, the hollow interior cavity 37 of the body 18 may define a polygonal shape having more or less than four sides such that the shape 43 is a polygonal shape having more or less than four sides. In one instance, at the specific cross-section XSi, the hollow interior cavity 37 of the body 18 defines a polygonal shape having five sides or more (e.g., a pentagon, a hexagon, a heptagon, an octagon, etc.). For instance, FIGS. 12A, 12B, 12C, 12D, 12E and 12F show specific cross-sections XSi in which the exterior surface 33 that is substantially rectangular (a rectangle with rounded corners (i.e., a rounded rectangle)) and the hollow interior cavity 37 of the body 18 define a pentagon, a hexagon, a heptagon, a decagon and a dodecagon, respectively. In another example, shown in FIG. 12G, at the specific cross-section XSi, the hollow interior cavity 37 of the body 18 defines a triangular shape (i.e., a polygonal shape having 3 sides). In another example of implementation and with reference to FIG. 12H, at the specific cross-section XSi, the exterior cross-sectional shape 15 defines a circle and the hollow interior cavity 37 of the body 18 defines a polygonal shape (e.g., a rectangular shape having rounded corners (i.e., a rounded rectangle), or any other polygonal shape in yet other examples). For instance, in some embodiments, at the specific cross-section XSi, the hollow interior cavity 37 of the body 18 defines a square with rounded corners (i.e., a rounded square).

[0094] In some embodiments, the rungs 26 are made of a material 21 that may be different from the material 29 of the elongated body 18 of the legs 16. In one example of implementation, the elongated body 18 is made of a composite material and the rungs 26 are made for a different material, such as for example a metallic material 19. In specific practical examples, the metallic material 19 may be made at least in part with aluminum and / or steel.

[0095] In some specific embodiments, which will be described with reference to FIGS. 13A and 13B, the rungs 26 are connected to the legs 16 at a connection 45. The connection 45 may be configured in any suitable fashion. In one embodiment, the connection 45 may be a reversable connection, in contrast to a permanent connection, which allows the rungs 26 to be disassembled from, and reassembled to, the legs 16 without damaging the rungs 26 and / or the legs 16. The connection 45 may be configured such that the material of the body 18 of the legs may be different than the material than the body 28 of the rungs 28.

[0096] In a specific example of implementation, the connection 45 may be a weld-free connection. For example, the connection 45 may be a mechanical connection (e.g., a connection including a mechanical fastener such as a bolted connection, a screwed connection, etc.). In some specific implementations, the frame 11 may comprise a plurality of connectors 47 for connecting the one or more rungs26 to the pair of legs 16. In one instance, the plurality of connectors 47 are brackets 109. In one example of implementation, the body 18 of the leg 16 includes openings 165 to receive fasteners 63 to fasten the brackets 109 to the leg 16 so as to fasten the rungs 26 to the legs 16.

[0097] The connectors 47 may be configured in any suitable fashion and may have any suitable shape and dimensions and be made with any suitable material or combination of materials. For instance, the connector 47 may be made, for example, of a metallic material (steel, iron, aluminum, etc.), plastics and / or plastic composites. The connector 47 may have any suitable shape (e.g., rectangular, square, circular, polygonal, elliptical, etc.). In one specific example, as shown in FIG. 13B, the connector 47 comprises a plate 101. In another specific example, as show in FIG. 13A, the connector comprises a U-shaped bracket 129.

[0098] The rungs 26 may be coupled to the connector 47 in any suitable fashion including through the use of mechanical fasteners, suitable engineering fits (e.g., interference fit, transition fit, etc.), by metal joining (e.g., welding, brazing, soldering, etc.), by adhesives, etc. In specific examples, the rungs 26 and the connector 47 may be integral with one another.

[0099] By configuring the connection between the rungs 26 and the legs 16 to be reversable, also referred to as releasable, the end frame assembly 12 may be configured for improved manufacturing, repair, maintenance, etc., by facilitating construction and servicing of the scaffold by reducing or eliminating the need for some skilled workers such as welders. Moreover, by configuring the connection between the rungs 26 and the legs 16 to allow the rungs 26 and or the legs 16 to be reversable, the scaffold 10 is more easily repairable. For example, if a single rung 26 of the scaffold is damaged, broken, deformed, etc., it is possible to replace that single rung 26 without replacing an entire ladder 14. As a result, repairs may be less costly and the usable lifespan of the scaffold 10 may be extended as compared to a scaffold configured with a permanent connection between the rungs 26 and / or the legs 16.

[0100] The legs 16 of the ladder 14 of the end frame assembly 12 may be constructed using any suitable process.

[0101] In a first specific example, the elongated body 18 of the leg 16 may be constructed by a pultrusion process.

[0102] With reference to FIG. 16, a specific pultrusion process 3000 is shown for manufacturing the legs 16 of the ladder 14 in accordance with a specific example of implementation. As shown, a continuous roll of reinforced fibers / woven fiber mat 3001 is fed into a pultrusion system 3012 as the raw reinforcing material. A tension roller 3002 ensures proper alignment and tension of the fibers as they pass through a resin impregnator 3003, where they are saturated with liquid resin 3010. The resin-soaked fiber 3011 exits the resin impregnator 3003 and is now ready for shaping and curing. The material 3011 enters a die and heat source 3005, where it is shaped and the resin is cured through heat to form a solid structure 3013. A pull mechanism 3006 continuously draws the solid structure 3013 through the die 3005 at a controlled rate. The process 3000 results in a finished hardened fiber reinforced polymer 3007, which exits as a continuous profile ready for cutting or further processing to form the legs 16 of the ladder 14. In this example, the solid structure 3013 pulled through the die 3005 forms an elongated structure with an exterior shape and a hollow interior cavity whose cross section may be of the type described in the present disclosure, for example with reference to FIGS. 10 and 12A to 12H.

[0103] In other specific examples, the elongated body 18 may be constructed by injection molding, plastic extrusion, continuous fiber extrusion or any other suitable manufacturing process for achieving an elongated body 18 of the type described in the present disclosure.

[0104] The end frame assembly 12 may be constructed using any suitable process. FIG. 15 is a flow diagram illustrating an example of a method 1600 for manufacturing an end frame assembly 12 of the type described in the present disclosure. At step 1610, the method 1600 includes forming a pair of legs by pultrusion of a composite material, each leg of the pair of legs comprising an elongated body having an exterior surface and an interior surface spaced from the exterior surface, the interior surface defining a hollow interior cavity extending along an extent of the elongated body, wherein at a specific cross-section taken transversely to the extent of the body, a distance between the exterior surface and the interior surface varies about a periphery of the hollow interior cavity. At step 1620, the method 1600 includes coupling one or more horizontal rungs to the pair of legs.

[0105] In one embodiment, coupling one or more horizontal rungs to the pair of legs includes coupling the one or more horizontal rungs by a releasable connector. In one example, coupling one or more horizontal rungs to the pair of legs includes coupling the one or more horizontal rungs using brackets.

[0106] In alternative implementations, the material 29 of the body 18 may comprise any other suitable material and may preferably comprise a material having a high strength to weight ratio and / or limited electroconductivity (e.g., a material with high resistivity, a material with low conductivity or no conductivity, etc.).

[0107] In some embodiments, any feature of any embodiment described herein may be used in combination with any feature of any other embodiment described herein.

[0108] Certain additional elements that may be needed for operation of certain embodiments have not been described or illustrated as they are assumed to be within the purview of those of ordinary skill in the art. Moreover, certain embodiments may be free of, may lack and / or may function without any element that is not specifically disclosed herein.

[0109] It will be understood by those of skill in the art that throughout the present specification, the term “a” used before a term encompasses embodiments containing one or more to what the term refers. It will also be understood by those of skill in the art that throughout the present specification, the term “comprising”, which is synonymous with “including,”“containing,” or “characterized by,” is inclusive or open-ended and does not exclude additional, un-recited elements or method steps. As used in the present disclosure, the terms “around”, “about” or “approximately” shall generally mean within the error margin generally accepted in the art. Hence, numerical quantities given herein generally include such error margin such that the terms “around”, “about” or “approximately” can be inferred if not expressly stated.

[0110] In describing embodiments, specific terminology has been resorted to for the sake of description, but this is not intended to be limited to the specific terms so selected, and it is understood that each specific term comprises all equivalents. In case of any discrepancy, inconsistency, or other difference between terms used herein and terms used in any document incorporated by reference herein, meanings of the terms used herein are to prevail and be used.

[0111] References cited in the specification, if any, are hereby incorporated by reference in their entirety for all purposes.

[0112] Although various embodiments of the disclosure have been described and illustrated, it will be apparent to those skilled in the art in light of the present description that numerous modifications and variations can be made. The scope of the invention is defined more particularly in the appended claims.

Claims

1. A scaffold comprising:a platform configured for supporting a user of the scaffold; anda frame for supporting the platform, the frame comprising a pair of end frames, each end frame in the pair of end frames comprising a pair of legs,wherein each leg of the pair of legs is comprised of an elongated body made of a composite material, the elongated body having an exterior surface and an interior surface spaced from the exterior surface, the interior surface defining a hollow interior cavity extending along an extent of the elongated body, wherein at a specific cross-section taken transversely to the extent of the body, a distance between the exterior surface and the interior surface varies about a periphery of the hollow interior cavity.

2. The scaffold of claim 1, wherein at the specific cross-section, the hollow interior cavity defines a constant radius.

3. The scaffold of claim 1, wherein at the specific cross-section, the hollow interior cavity defines a circular shape.

4. The scaffold of claim 1, wherein at the specific cross-section, the hollow interior cavity defines a polygonal cross-sectional shape comprising five or more sides.

5. The scaffold of claim 1, wherein the interior surface is comprised of reinforcing portions disposed within the elongated body.

6. The scaffold of claim 1, wherein the elongated body is an elevated rectangular body.

7. The scaffold of claim 1, wherein at the specific cross-section, the exterior surface of the elongated body forms a rectangular shape.

8. The scaffold of claim 1, wherein at the specific cross-section, the exterior surface of the elongated body forms a square shape.

9. The scaffold of claim 1, wherein at any cross-section taken transversely to the extent of the elongated body, the distance between the exterior surface and the interior surface varies about the periphery of the hollow interior cavity.

10. The scaffold of claim 1, wherein the elongated body is constructed by a pultrusion process.

11. The scaffold of claim 1, wherein the composite material comprises a fiberglass reinforced polymer material.

12. The scaffold of claim 1, wherein the composite material comprises an aramid reinforced polymer material.

13. The scaffold of claim 1, wherein a load-to-weight ratio of the scaffold is greater than 7.

514. The scaffold of claim 1, wherein the load-to-weight ratio of the scaffold is about 8.

15. The scaffold of claim 1, wherein the scaffold further comprises one or more rungs extending between the pair of legs.

16. The scaffold of claim 15, wherein a material of the one or more rungs is different than the composite material of the body.

17. The scaffold of claim 16, wherein the material of the one or more rungs comprises aluminum.

18. The scaffold of claim 16, wherein the material of the one or more rungs comprises steel.

19. The scaffold of claim 15, wherein the one or more rungs is connected to the pair of legs at a weld-free connection.

20. The scaffold of claim 19, wherein the frame comprises a plurality of connectors for connecting the one or more rungs to the pair of legs.

21. The scaffold of claim 20, wherein the plurality of connectors includes brackets.

22. An end frame for a scaffold, the end frame comprising:a pair of legs, each leg of the pair of legs being comprised of an elongated body made of a composite material, the elongated body having an exterior surface and an interior surface spaced from the exterior surface, the interior surface defining a hollow interior cavity extending along an extent of the body, wherein at a specific cross-section taken transversely to the extent of the body, a distance between the exterior surface and the interior surface varies about a periphery of the hollow interior cavity; andone or more rungs extending between the pair of legs.

23. A method of manufacturing an end frame for a scaffold, the method comprising the steps of:forming a pair of legs by pultrusion of a composite material, each leg of the pair of legs comprising an elongated body having an exterior surface and an interior surface spaced from the exterior surface, the interior surface defining a hollow interior cavity extending along an extent of the elongated body, wherein at a specific cross-section taken transversely to the extent of the body, a distance between the exterior surface and the interior surface varies about a periphery of the hollow interior cavity; andcoupling one or more horizontal rungs to the pair of legs.

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