Connectable Multi-Function Scaffold

Abstract

A lightweight, multifunction scaffold comprises first and second ladder frames, and an adjustable height platform configured to be supported between the first and second ladder frames at a user selected height in an adjustment range. The multifunction scaffold can be linked together end to end with other similar scaffolds to provide a longer working surface.

Claims

1. A scaffold comprising: an adjustable height platform; a first ladder frame supporting a first end of the adjustable height platform, the first ladder comprising: a first pair of vertical supports; a first set of fixed ladder rungs connecting the first pair of vertical supports and providing access to the adjustable height platform up to a first predetermined height; a pass-through between the vertical supports of the first ladder frame above the first set of fixed ladder rungs allowing a user to step between the vertical supports onto or off of the adjustable height platform when the platform is adjusted to the first predetermined height below a maximum height. a second ladder frame supporting a second end of the adjustable height platform, the second ladder frame comprising a second pair of vertical supports connected by a second set of fixed ladder rungs extending above the first predetermined height and providing access to the adjustable height platform above the first predetermined height.

2. The scaffold of claim 1, wherein the second ladder frame has a different number of fixed ladder rungs than the first ladder frame.

3. The scaffold of claim 2, wherein the first ladder frame comprises not more than two fixed ladder rungs and the second ladder frame comprises three or more fixed ladder rungs.

4. The scaffold of claim 1, wherein the pass-through is vertically unobstructed above the top ladder rung of the first ladder frame.

5. The scaffold of claim 1, wherein the adjustable height platform comprises: a pair of reversible side rails configured to be supported between the first and second ladder frames in a first orientation and a second orientation, each side rail including first and second support surfaces disposed on opposite sides of an axial plane dividing the side rail into upper and lower portions; a deck configured to mount between the side rails so as to be supported by the first support surfaces when the siderails are in the first orientation and by the second support surfaces when the siderails are in the second orientation; and a pair of guide channels at opposing ends of each side rail for slidably mounting the side rails to the vertical supports of the first and second ladder frames respectively.

6. A ladder frame for a scaffold having an adjustable height platform, the ladder frame comprising: a pair of vertical supports; one or more ladder rungs connecting the vertical supports and providing access to the adjustable height platform up to a predetermined height below a maximum height of the adjustable height platform; a pass-through between the vertical supports of the ladder frame above the top ladder rung allowing a user to step between the vertical supports onto or off of the adjustable height platform when the platform is adjusted to a first predetermined height below a maximum height.

7. The scaffold of claim 6, wherein the pass-through is unobstructed in the vertical direction above the uppermost ladder rung.

8. The scaffold of claim 7, wherein the first ladder frame comprises not more than two fixed ladder rungs.

9. A scaffold assembly comprising: first, second and third ladder frames, each ladder frame comprising two vertical supports connected by one or more fixed ladder rungs; a first adjustable height platform configured to be supported between the first and second ladder frames; a second adjustable height platform configured to be supported between the second and third ladder frames while the first adjustable height platform is mounted between the first and second ladder frames; wherein the second ladder frame comprises a pass-through between the vertical supports of the first ladder frame allowing a user to step between the vertical supports from a first one of the adjustable heights platforms to the other one of the adjustable height platforms.

10. The scaffold assembly of claim 9, wherein: the first adjustable platform comprises: a first pair of side rails configured to be supported between the first and second ladder frames, each side rail of the first pair including a first support surface; a first deck configured to mount between the first pair of side rails so as to be supported by the first support surfaces; first guide channels at opposing ends of each side rail in the first pair of side rails for slidably mounting the first pair of side rails to respective the vertical supports of the first and second ladder frames; and the second adjustable height platform comprises: a second pair of side rails configured to be supported between the second and third ladder frames, each side rail of the second pair including a second support surface; a second deck configured to mount between the second pair of side rails so as to be supported by the second support surfaces; second guide channels at opposing ends of each side rail in the second pair of side rails for slidably mounting the second pair of side rails to respective vertical supports of the second and third ladder frames with the second pair of side rails disposed in an opposite orientation to the first pair of side rails.

11. The scaffold assembly of claim 10, wherein the guide channels of the first and second adjustable height platforms are configured to enable the adjustable height platforms to be adjusted to the same level when used at the same time.

12. The scaffold assembly of claim 9, wherein the first and third ladder frames have a different number of fixed ladder rungs.

13. The scaffold assembly of claim 9, wherein: the first ladder frame includes a first number of fixed ladder rungs providing access to the first adjustable height platform when the first adjustable height platform is adjusted to a first predetermined height; and the third ladder frame includes a second number of fixed ladder rungs greater than the first number and providing access to the second adjustable height platform when the second adjustable height platform is adjusted to a second predetermined height greater than the first predetermined height.

14. The scaffold assembly of claim 13, wherein: the first ladder frames includes a pass-through between the vertical supports of the first ladder frame above the fixed ladder rungs allowing a user to step between the vertical supports onto or off of the first adjustable height platform when the first adjustable height platform is adjusted to the first predetermined height below a maximum height. The third ladder frames each includes a pass-through between the vertical supports of the first ladder frame above the fixed ladder rungs allowing a user to step between the vertical supports onto or off of the second adjustable height platform when the second adjustable height platform is adjusted to the first predetermined height below a maximum height.

15. The scaffold of claim 9, wherein the pass-through is vertically unobstructed above the fixed ladder rungs of the first ladder frame.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] FIG. 1 is a perspective view of a multi-function scaffold with the platform in a first orientation.

[0010] FIG. 2 is a perspective view of a multi-function scaffold with the platform in a second orientation.

[0011] FIG. 3 is a perspective view of two multi-function scaffolds connected together end-to-end with the platforms at the same height.

[0012] FIG. 4 is an elevation view of two multi-function scaffolds connected together end-to-end.

[0013] FIG. 5A is a perspective view of a ladder frame for the multi-function scaffold.

[0014] FIG. 5B is an side view of a ladder frame for the multi-function scaffold.

[0015] FIG. 6A is a perspective view of a walk-through ladder frame for the multi-function scaffold.

[0016] FIG. 6B is an side view of a ladder frame for the multi-function scaffold.

[0017] FIG. 7 is a perspective view of a side rail assembly for the multi-function scaffold.

[0018] FIG. 8 is an elevation view of a side rail assembly for the multi-function scaffold.

[0019] FIG. 9 is a detail partial perspective view of a side rail assembly for the multi-function scaffold.

[0020] FIG. 10 is a cross-section of a side rail for the multi-function scaffold.

[0021] FIG. 11 is a partial top view of a side rail for the multi-function scaffold showing a slot for a locking pin.

[0022] FIG. 12 is a perspective view of a locking pin for the multi-function scaffold.

[0023] FIG. 13 is an elevation view of the locking pin for the multi-function scaffold.

[0024] FIG. 14 is a perspective view illustrating installation of a locking pin.

[0025] FIG. 15 is a partial perspective view of two multi-function scaffolds connected together end-to-end.

[0026] FIG. 16 is a partial perspective view showing details of the side rail assemblies in the end-to-end connection of FIG. 15.

[0027] FIG. 17 illustrates a 22 stack of multi-function scaffolds.

[0028] FIG. 18 illustrates a 23 stack of multi-function scaffolds.

[0029] FIG. 19 is a perspective view of two multi-function scaffolds connected together end-to-end with the platforms at different heights.

DETAILED DESCRIPTION

[0030] Referring now to the drawings, a multi-purpose scaffold 10 according to an exemplary embodiment is shown. The multi-purpose scaffold 10 comprises two ladder frames 20, 20 and an adjustable height platform 40 supported between the two ladder frames 20. In one embodiment, one of the ladder frames is a conventional ladder frame 20 and the other is a walk-through ladder frame 20. The adjustable height platform 40 can be mounted between the ladder frames 20, 20 in two different orientations depending on a height requirement for a task. The first orientation, shown in FIG. 1, enables the platform 40 to be adjusted to its maximum height. The second orientation, shown in FIG. 2, enables the platform 40 to be adjusted to its minimum height. As will be hereinafter described, the ladder frames 20, 20 enable a worker to easily access the platform 40 at any height while meeting OSHA climb requirements.

[0031] FIGS. 3 and 4 show two scaffolds 10 connected end-to-end to form a larger scaffold with the platforms 40 adjusted to the same height. In this case, the two scaffolds 10 share a walk-through ladder frame 20 so that the combined scaffold includes three ladder frames 20 and two platforms 40. The platforms 40 of the two scaffolds 10 can be adjusted to the same height to prevent a trip hazard when moving between scaffolds 10. The walk-through ladder frame 20 enables workers to easily move between adjacent platforms 40 without obstruction.

[0032] FIG. 19 shows two scaffolds 10 connected end-to-end to form a larger scaffold with the platforms 40 adjusted to different heights. In addition to the shared walk-through ladder frame 20 between the connected scaffolds 10, the configuration shown in FIG. 19 includes walk-through ladder frames 20 both ends as well between the scaffolds 10 to enable easier access to the platforms 40 of the scaffolds 10 at different heights. The walk-through ladder frames 20 on opposite ends have a different number of fixed ladder rungs 24 providing access to the platforms 40 at different levels. In the embodiment shown, one ladder frame 20 comprises two fixed ladder rungs providing access the lower platform 40 at a first predetermined height, and the other ladder frame comprises three fixed ladder rungs providing access to the higher platform at a second predetermined height.

[0033] FIGS. 6A and 6B illustrate a conventional ladder frame 20 used at one end of the multi-function scaffold 10. The conventional ladder frame 20 comprises two vertical supports 22 connected by two or more cross members 24 that serve as fixed ladder rungs. The components of the ladder frame 20 are preferably made of a metal tubing or other tubular material welded together to form a unitary structure so that the fixed ladder rungs are not removable.

[0034] FIGS. 5A and 5B illustrate an exemplary walk-through ladder frames 20. The walk-through ladder frame 20 comprises two vertical supports 22 connected by two or more cross members 24 that serve as ladder rungs. Vertical handrails 26 extended upward from the uppermost cross member 24. The upper end of the handrails 26 are bent outward and join with respective ones of the vertical supports 22. Short rungs 28 connect the handrails 26 with the vertical supports 22 and serve and handholds for persons climbing on and off the scaffold 10. The components of the walk-through ladder frame 20 are preferably made of a metal tubing or other tubular material welded together to form a unitary structure.

[0035] The spaced-apart handrails 26 of the walk-through ladder frame 20 provide an opening 30 referred to herein as a pass-through 30 that serves as a means of ingress to and egress from the platform 40. The pass-through 30 is unobstructed in the vertical direction above the uppermost crossmember 24, i.e., is open at the top. A person climbing onto the scaffold 10 may step between the handrails 26 onto the platform 40 while holding onto the handrails 26. Similarly, a person climbing down from the scaffold 10 may step between the handrails 26 onto the cross-member 24 of the walk-through ladder frame 20 while holding the handrails 26. When two scaffolds 10 are joined as shown in FIGS. 3 and 4, the opening 30 between the handrails 26 on the shared walk-through ladder frame 20 allows the worker to step between the handrails 26 from the platform 40 on one scaffold 10 onto the platform 40 of an adjacent scaffold 10.

[0036] In both the conventional ladder frame 20 and walk-through ladder frame 20, a series of aligned openings 32, best shown in FIGS. 5B and 6B, extend through the vertical supports 22 perpendicular to the plane of the ladder frame 20, 20 and are spaced apart, such as by being spaced two inches apart. As will be hereinafter described in more detail, the openings 32 are engaged by a releasable locking mechanism 60 on the platform 40 to secure the platform 40 at a desired height between the ladder frames 20, 20. Additionally, openings 34 (FIGS. 5A and 6A) extend transversely through the lower end of each vertical support 22. These openings 34 are used to secure casters 36 to the vertical supports 22 when the platform 40 is in the lowermost position as will be hereinafter described.

[0037] When the scaffold 10 is used in standalone fashion, a conventional ladder frame 20 can be used at one end of the scaffold 10 and a walk-through ladder frame 20 can be used at the opposite end. The walk-through ladder frame 20 provides OSHA-complaint access to the adjustable height platform up to a predetermined height, which is approximately 16.5 inches above the last uppermost cross member 24. The conventional ladder frame 20 provides OSHA-compliant access above the predetermined height. In this way, workers can access the adjustable height platform 40 by stepping through the walk-through ladder frame 20 when the adjustable height platform is at or below the predetermined height while the conventional ladder frame 20 provides OSHA-compliant access above the predetermined height.

[0038] The adjustable height platform 40 comprises two side rail assemblies 42 that extend between the ladder frames 20, 20 and a deck 70 that is supported by the side rail assemblies 42. The side rail assemblies 42 are designed to slide along the vertical supports 22 of the ladder frames 20, 20. A locking mechanism locks the side rail assemblies at the desired height. An exemplary side rail assembly 42 is illustrated in FIG. 7-11. As previously noted, the side rail assemblies 42 in the illustrated embodiment are reversible. It will be noted, however, that some embodiments may not require the side rail assemblies 42 to be reversible. For example, reversibility is not required when the side rail assemblies 42 are mounted on the same ladder frame 20, 20 at different heights. Other embodiments are also contemplated where the side rail assemblies 42 are configured to mount simultaneously to the same ladder frame and adjusted to the same height.

[0039] Returning to FIG. 7-11, each side rail assembly 42 comprises a side rail 44 and two guide channels 50 connected at opposite ends of the side rail 44. A brace 46 extends between the side rail 44 and guide channel 50 to provide strength and rigidity. The ends of each side rail 44 connect directly or indirectly to a C-shaped guide channel 50 sized to fit around the vertical supports 22 of the ladder frames 20. In one embodiment, an optional square sleeve 48 is interposed between each end of the side rail 44 and the guide channel 44 for mounting a safety rail to the platform 40. The sleeve 48 is configured to receive posts for a safety rail (not shown), which can be inserted into the sleeve 48 and secured by any suitable means, such as a toggle pin. The components of the side rail assembly 42 including the side rail 44, sleeves 48, braces 46, and guide channels 50 are preferably made of aluminum or other lightweight metal alloy and welded together to form a unitary structure.

[0040] In one embodiment, the side rails 44 comprise elongated channels or beams extruded from aluminum or other lightweight metal or metal alloy. The side rails 44 are configured to provide a support surface for the deck 70 in two orientations, referred to herein as the normal orientation (FIG. 1) and inverted orientation (FIG. 2).

[0041] FIG. 10 shows a cross-section of an exemplary siderail 44. In this embodiment, the side rail 44 comprises a central web 44a with two stepped flanges 44b having multiple bends. The steps in the flange 44b closest to the central web 44a provide support surfaces 44c for supporting the deck 70 in the first and second orientations respectively. The vertical segments 44d adjacent the support surfaces 44c serve as retaining walls to contain the deck 70 in place. The siderail 44 in the illustrated embodiments is symmetrical about an axial plane that extends horizontally (i.e., parallel to deck 70) and divides the siderail 44 into an upper portion (above the axial plane) and a lower potion (below the axial plane). The upper and lower portions switch depending on the orientation of the siderail 44.

[0042] Referring back to FIG. 9, the guide channels 50 comprises a C-shaped channel configured to slide along the vertical supports 22 of the ladder frames 20 at each end of the scaffold 10 to adjust the height of the platform 40. The guide channel 50 comprises a central web 52 with two flanges 54. Aligned openings 56 are formed in the flanges 54 of each guide channel 50 for locking the guide channel 44 at a selected height as hereinafter described. The openings 56 are spaced to align with the openings 32 in the vertical supports 22 of the ladder frame 20, 20 at preselected heights. The openings 56 in the guide channels 50 are engaged by a releasable locking mechanism 60 (described below) on the platform 40 to secure the platform 40 at a desired height between the ladder frames 20.

[0043] The guide channels 50 connect to the siderail 44 (or to the sleeve 48 if present) in an offset manner so that the end face 51 (FIG. 9) at the proximal end of the guide channel 50 does not extend beyond the axial plane of the siderail 44. A triangular gusset 55, connects along one edge to the guide channel 50 and an adjacent edge to the siderail 44 (and sleeve 48 if present) to provide strength and rigidity to the siderail assembly 42.

[0044] The offset connection enables two siderail assemblies 42 to be installed on the same vertical support 22 in opposite orientations and adjusted in height so that the first support surface of the siderail 44 in a first orientation is level with the second support surface of the siderail 44 in the second orientation. This feature enables the platforms 40 on two connected scaffolds to be adjusted to the same level as shown in FIGS. 3 and 4. In one embodiment, the end face 51 of the guide channel 50 lies in the axial plane of the siderail 44. In this case, when two sideral assemblies 42 are mounted in opposite orientations on the same vertical support 22 and adjusted to the same height, the end faces 51 of the guide channels 50 abut. Alternatively, the end faces 51 are angled relative to a vertical axis of the guide channel 50 so that a first portion of the end face 51 is below the axial plane and a second portion of the end face 51 is above the axial plane. Assuming that the geometric center of the end faces 51 lie in the axial planes of the respective siderails 44, the angled end faces 51 would abut when two sideral assemblies 42 are mounted in opposite orientations on the same vertical support 22 and adjusted to the same height. In other embodiments, the geometric center of the end faces 51 can be offset from the axial plane so that there is a gap between the end faces 51 when two sideral assemblies 42 are mounted in opposite orientations on the same vertical support 22 and adjusted to the same height.

[0045] FIG. 9 illustrates the releasable locking mechanism 60 according to an embodiment. The releasable locking mechanism 60 comprises a U-shaped latch 62 that engages with the aligned openings 56, 32 in the guide channel 44 and vertical supports 22 respectively to lock the side rail 44 at a desired height. Each latch 62 includes a pair of spaced apart legs 62a connected by a cross member 62b. The latch 62 is supported by a bracket 64 and biased by springs 68 surrounding each leg 62a of the latch 62 to a locked position. The springs 68 are compressed when the latch 62 is pulled back to disengage the latch 62 and push the latch 62 back to an engaged position when the latch 62 is released.

[0046] In some embodiments, additional openings 58 are formed in the central web 52 of the guide channel 50. Openings 58 align with openings 34 in the vertical supports 22 when the platform 40 is lowered so that the span pin securing the casters to the vertical supports 22 can be inserted.

[0047] When the side rail assemblies 42 are mounted between the ladder frames 20 and adjusted to the same height, the deck 70 can be placed between the side rails 44. As previously noted, the deck 70 is supported by the supports surfaces 44c of the side rails 44. The side rails 44 are equipped with latches 80 (also referred to as locking pins or locking pin assemblies) to secure the deck 70 in place after the deck 70 is installed. FIGS. 1 and 2 show the side rail assemblies 42 with the deck 70 and latches 42 installed.

[0048] FIG. 11-14 illustrate the deck latch mechanism. As shown in FIG. 11, specially-formed slots 45 are formed in the second step 44e of the flanges 44b of the side rail 44. The slots 45 in the flanges 44b are vertically aligned. As explained in more detail below, the latches 80 can be installed in the vertically-aligned slots 45 in both the first and second orientations.

[0049] Each slot 45 includes an elongated narrow channel 45a having a relatively larger hole 45c formed near one end of the channel 45a and a relatively smaller hole 45b formed near the opposing end of the channel 45a. The smaller hole 45b is sized to match the outer diameter of the shaft 82 of latch 80. The holes 45b, 45c located along the length of the channel 45a facilitate installation of the latch 80 as herein described. When a need arises to reverse the platform 40, the latches 80 can be removed and re-installed in the new orientation without use of any tools. This eliminates the need to have separate latch mechanisms for use in each orientation.

[0050] FIGS. 12 and 13 illustrate an exemplary latch 80. The latch 80 comprises a shaft 82 with a catch element 84 at one end. The shaft 82 includes a reduced diameter section 86 near the end proximate the catch element 84 and a pair of spaced openings 88 to receive respective roll pins 90, each of which forms one or more protrusions on the shaft 82. When the latch 80 is installed on the side rail 44, a biasing member (e.g., a coil spring 92) biases the catch element 84 into engagement with the deck 70 to prevent the deck 70 from lifting off the support surface 44c. The spring 92 bears at one end on the inside of the flange 44b and at the other end on a roll pin 90. Optionally, a bushing 94 can be interposed between the spring 92 and the inner surface of the flange 44b to prevent the starting coil at top of the spring 92 from accidentally threading itself up through smaller hole 45b in the slot 45 when the latch 80 is installed.

[0051] No tools are required to remove and install the latch. The latch 80 is installed by inserting it at an angle through vertically aligned upper and lower slots 45 and then sliding the upper end of the latch 42 along the upper slot 45 to a vertical position. The shaft 82 is inserted at an angle through the larger hole 45c in the upper slot 45, which is sized to allow the shaft 82 and spring 92 to pass through the slot 45, with the lower end passing through the smaller hole 45b in the lower slot 45. Note that shaft 82 is oriented so that the protrusions 90 are aligned with the channel 45a so that the protrusions 90 (e.g., roll pin) can fit through the slot 45. After the latch 80 is inserted at an angle, the latch 80 is rotated so that the protrusions 90 in the lower end of the shaft 82 extends generally perpendicular to the channel 45a and the lower most protrusion 90 prevents withdrawal of the latch 42. The upper end portion of the shaft 82 can then slide along the channel 45a until the shaft 82 is vertically oriented in the small hole 45b in both the upper and lower slots 45. To achieve this, the collar 94 is pulled down away from the catch element 84, so that there is a gap between the collar 94 and the catch element 84 large enough to expose the reduced diameter section 86. Once exposed, the reduced diameter section 86 can slide into and along the channel 45a of the upper slot 45 (between the larger hole 45c and the smaller hole 45b) until the shaft 82 is vertically aligned with the smaller hole 45b of the upper slot 45. The collar 94 may be released at this point, or may be released once the reduced diameter section 86 is in the channel 45a. In this way, the upper end of the shaft 82 is moved away from the larger hole 45c of the upper slot 45 toward the smaller hole 45b of the upper slot 45, while the lower end of the shaft 82 remains in the smaller hole 45b of the lower slot 45. When the force compressing the spring 92 is removed, the spring 92 pushes latch 80 down so that the shaft 82 engages with the smaller holes 45c in the slot 45.

[0052] To install the deck 70, the latch 80 is pushed up slightly to rotate the latch 80 so that the catch element 84 moved out of the way. Once the deck 70 is put into place, the latch 80 is rotated so that the catch element 84 extends over and engages the top of the deck 70. The deck preferably includes recesses 72 in the upper surface to engage with the catch element 84 so that the catch element 84 will be flush with or below the surface of the deck 70. Providing a recess 72 in the deck 70 reduces the tripping hazard and further reduces the likelihood that the catch element 46 will be accidentally kicked and disengaged.

[0053] In some embodiments, the scaffold 10 includes casters 90 or other ground-engaging members disposed at the lower end of each vertical support 22. The casters 90 are secured by span pins that pass through aligned openings in the caster 90 and vertical support 22 respectively to secure the caster 90 to the vertical support 22. Because the casters 90 are not material to the disclosure, further discussion of the caster is omitted. More details regarding the casters 90 can be found in U.S. Patent Application Publication No. 2023/0151620 (Application No. 18/097349), which is incorporated herein in its entirety by reference.

[0054] FIGS. 17 and 18 illustrate exemplary stacking configurations for the multi-function scaffold. In FIG. 17, four multi-function scaffolds 10 are stacked in a 22 configuration, with two scaffolds 10 on each of two levels. On each level, a walk-through ladder frame 20 is used between the connected scaffolds 10 to enable a worker to move between the scaffolds 10. A conventional ladder frame is used at one end of the lower level to enable workers to climb up to the second level.

[0055] In FIG. 18, six multi-function scaffolds 10 are stacked in a 23 configuration, with two scaffolds 10 on each of three levels. On each level, a walk-through ladder frame 20 is used between the connected scaffolds 10 to enable a worker to move between the scaffolds 10. A conventional ladder frame is used at one end of the first and second levels to enable workers to climb up to the top level.