CA2158199C - Scaffolding plank - Google Patents

Abstract

A work plank for work platforms, access scaffolding walkways and the like structures has an elongate metal channel defining a top surface supported by downwardly and inwardly extending sidewalls. The top surface preferably has a series of ports providing aggressive traction. Hook arrangements can be provided at the ends of the channel for supporting the metal channel from access scaffolding. The inwardly angled sidewalls improve strength, reduce the sensitivity of the plank to damage and assist in locating of the planks. In a preferred embodiment, the hook arrangements also cooperate with drop-in ramps for providing transitions, when required.

Description

T;H 9395CA 2 TITT.E: st~FF~T~nINc; pT ~NK
FTT.T n OF TT-TT~`. TNVENTION
The present invention relates to a work plank for 5 uge in definlng a ralsed work surface. In particular, the work plank is for use in associatLon wlth access scaffolding and similar structures.
R~`Rt~T~QTTNn OT~' TTTE INV~NTION
Traditlonally, wooden boards have been used for deflning work surfaces on scaffolding. These boards can become damaged and the surface of the boards can deteriorate, reducing traction. Various metal members have been secured to the ends of the boards for positively supporting the boards on a scaffold framework.
There have been a number of steel work planks which have been proposed where the upper surface of the plank has been provided with various ports to provide an aggressive traction surface and to also provide water drainage from the upper surface of the plank. These steel planks are typically of a channel shape to provide sufficient structural stiffness and closed at the ends by hook arrangements. Examples of such steel planks are shown in United Kingdom Patent Application No. 2 055 944 and United Kingdom Patent No. 1 352 697.
In some scaffolding applications, it is difficult for the scaffolding framework to be set up to follow the contours of the structure. For example, access scaffolding can be used to define a work surface about a large cylindrical storage tank. In these circumstances, it is often necessary to provide a work surface comprised of spaced rectangular areas and then use additional work planks to form a transition surface between these rectangular areas which more closely follows the contour of the structure. In this type of system, although the second surface does improve the safety of the work platform in that there are less gaps where accidents can occur, the W~-9395CA ~ 9~
.
work planks at the ends thereof do provide a ledge which can lead to tripping. In some instances, when using wooden scaffolding planks, single use, custom fitted, plywood ramps are nailed to the planks. These ramps form a 5 transitlon between the first work surface and the work surface supported thereabove.
Although steel work planks have been used, they have not proven entirely satisfactorily and many applications still use wooden planks.
SJMM~RY OF TTTF INVFNTION
A work plank according to the present inventlon is for use in association with work platforms, access scaf folding, walkways and the like structures and comprises 15 a metal channel having a top surface and opposed sidewalls.
The opposed sidewalls of the plank are angled inwardly to oppose outward bowing of the sidewalls during loading of the work plank.
In a preferred embodiment, the top surface has a 20 plurality of openings angled out of the top surface to provide aggressive traction surfaces.
In yet a further aspect of the invention, the work plank, at either end thereof, has a hook arrangement for engaging a cylindrical support. Each hook arrangement 25 continues the channel configuration of the metal channel and is mechanically secured to the metal channel.
According to an aspect of the invention, each hook arrangement is secured by mechanical fasteners passing through the sidewalls with the angled sidewalls providing 30 sufficient clearance for the mechanical fastener to pro~ect beyond the sidewall while being located within the width of the top surface of the work plank.
According to a further aspect of the invention, the sidewalls intermediate the hook arrangement include a 35 keyhole for receiving a key used to fasten two planks located in a side by side configuration.

W-9~9SCA
According to yet a further aspect of the invention, each hook arrangement includes a port through an upper surface thereof which cooperates with a ramp member to positively retain the ramp member in an operative position 5 relative to the plank.
BRTR~ D~SCRIPTION OF T~l~. DRAWINGS
Preferred embodiments of the invention are shown in the drawings, wherein:
~igure 1 is a perspective view of the channel member of the work plank;
Figure 2 is a partial sectional view of a traction port along line A-A of Figure 1;
Figure 3 is a partial sectional view along part of line B-B of Figure 1;
Figure 4 is a partial perspective view of a hook arrangement about to be received in a channel member;
Figure 5 is a partial perspective view of a hook arrangement received in the channel member of Figure 1;
Figure 6 is a partial perspective view of a ramp about to be secured to a work plank;
Figure 7 is a partial perspective view showing a lower work surface of planks supporting a further work plank thereabove;
Figure 8 is a perspective view of a tie-down member used in Figure 6;
Figure 9 is a sectional view of a key securing two adjacent work planks;
Figure 10 is a sectional view of the channel member as formed;
Figure ll is a view similar to Figure 10 showing how the channel adjusts when a hook arrangement is inserted into the channel member; and Figure 12 is a top view of a double ramp used to secure two work planks.

~ g DETATTlT~n DT~CP~TPTION OF T~IT pRT~T~ERRRn EMPODIMTMTS
The work plank 2 is primarily formed by the metal channel section 4 having an upper surface 6 and downwardly and inwardly angled sidewalls 8. These sldewalls have an inwardly rolled edge 9 which defines a narrow channel 11 between edge 13 and the sldewall 8. Channel ll will serve to retain a latch member, which will subsequently be described .
The channel can be made of flat steel which is rolled to form the channel shape. High strength steel having a thickness of about .060 thousandth of an inch and a yield strength of about 50, 000 lb/in2 has proven satisfactory for many applications.
The upper surface of the work plank 2 has a series of outwardly pro~ecting holes 14 to provide aggressive traction on the upper surface and the upper surface also has a series of reinforcing ribs 18 which are recessed with a central drainage opening 16. The reinforcing ribs 18 have been found to stiffen the metal channel section 4.
As an alternative to the ribs and drainage port, the planks can be rolled to form a convex surface whereby water drains off of the plank. This shape also adds stif fness .
The sidewalls 8 extend downwardly and inwardly and this particular configuration has improved characteristics with respect to the structural strength thereof. By angling the walls downwardly and inwardly, there is less tendency for the channel section to fail by outward .v~ -nt of the sidewalls 8, thereby tending to flatten the channel, which is a common mode of failure for ~-hAnnel 1 ed structures. In addition, the downwardly inwardly angled sidewalls allow adjacent planks to generally abut at the upper surface with some clearance being provided between the sidewalls 8. Therefore, if any of the sidewalls become slightly damaged or the sidewalls are distorted slightly outwardly, the planks will still abut at the upper edge.
The rolling of the sidewalls at the bottom edge also WH--93gSCA ~8 L ~
reinforces the plank and essentially defines two rails at the lower surface. This ls also an improvement, as these rails act as support rails if one plank is ~tacked atop another plank or across another plank. This possibility of 5 having planks on top of planks is ~uite common where the access scaffolding is used to provide a work surface about an irregular ob~ect, such as a circular tank. Furthermore, the rails reinforce the plank thereby making it less vulnerable when transported or stored. The planks 10 preferably are about one foot in width and up to about ten feet in length.
Loading of the planks tends to force the sidewalls to distort inwardly, which in turn tends to bow the working surface of the plank upwardly. This, surprisingly, 15 increases the effective transverse stiffness (side to side) which allows the plank to be made from thinner material, thereby reducing weight and cost.
The work plank 2, as shown in Figures 4 and 5, includes hook arrangements 10 located at opposite ends of 20 the work plank for securement with a cylindrical steel transom or the like of a scaffold frame. Each hook arrangement 10 includes a pro ~ecting hook portion 38 for engaging a cylindrical transom member. Engaging hook portion 38 includes a port 39 for engaging and retaining a 25 ramp 50.
The sidewalls 8 include diamond shaped keyholes 30 for receiving a fastening key 32, as shown in Figure 9.
The keyhole is preferably at least located in a fixed central location whereby two work planks in side by side 30 relationship can be tied together and thus deflect together when a key passe~ through each of the keyholes 30, as shown in Figure 9. The fastening key 32 is designed to pass through the keyholes in a first orientation and then be rotated to a second orientation approximately 90 away from 35 the first orientation, and in this second orientation ties the work planks together. Keying of the work planks also serves to maintain the planks in side by side rf~l~t1f~n~h~p w 395c~
and forces the planks to deflect together. For example, as a worker steps down on the center portLon of one work plank, both planks tend to support each other and distribute the load, even if the worker is standlng on a 5 single work plank. This is important in that the work planks can be designed for spans of up to ten feet and there can be considerable deflection in the center of the work plank, particularly when the work plank is supported by transoms at either end. This combined strength 10 obviously includes the effect of a third work plank located on the opposite side, if present.
As shown in Figures 4 and 5, the angled sidewalls 8 have a securing port 5 through which a self-taping, fastening member 7 passes to engage port 15 in sidewall 47 15 of the hook arrangement to thereby secure the hook arrangement at the end of the plank. The angled sidewall 8 of the channel 4 allows the head of the fastener 7 to pro~ect from the sidewall while still providing full clearance between adjacent planks ~see Figure 6). The 20 fastener 7 preferably is of a self-tapping design to engage the sidewall 47 of the hook arrangement as the fastener passes therethrough. The fastener also pro~ects and is of a length to locate the wind latch 70. The wind latch 70 has a slot 72 through which the fastener 7 passes. The 25 wind latch is slidable on the fastener 7 and is retained in the channel 11 and is thus trapped to the work plank (see Figure 5). In this way, there is no need to have additional fasteners retain the latch to the work plank and the wind latch is easily movable along the fastener 7. The 30 latch is movable from a fully locked position where the latch has the forward edge 74 positioned below a transom of a scaffoId frame to a clear position shown in dotted lines.
There is no spring loading of the latch, as in some circumstances, such as for indoor scaffolding, actual 35 latching of the plank may not be required. It can also be seen that the wind latch 70 ;nf~ 5 a camming surface 76 at the forward end, such that when a work plank is dropped WH--935~CA
on a transom, it is plvotted upwardly and forced into the work plank to a clear position. In this way, the worker does not have to manually move the latch to a clear position. Should the worker wish to latch the plank to the 5 transom, the latch can then be moved to the engaged pos ition .
Figure 9 shows how the key 32 can engage the sidewalls 8 of ad~acent side by side work planks 2. By tying of the work planks together, any outward failing of 10 the sidewalls 8 i5 limited by contact with the ad~acent work plank and any inward movement of the sidewalls is also restricted, as the key restricts this movement in the locked position as the head 35 engages the lower rail of one work plank and the tail 37 engages the rail of the 15 other work plank. It can also be appreciated that this lower edge of the work planks is relatively stiff due to the rails 9.
Details of the hook arrangement are shown in Figures 4, 5 and 6. Each hook arrangement lO has an upper 20 surface 45 and downwardly extending, inwardly angled sidewalls 47. The sidewalls 47 are not at a constant depth and have a tapered portion, generally shown as 49, along the bottom edge. This allows the hook arrangement to be initially fed into the end of a work plank, as there is 25 additional clearance due to the tapered edge, and the hook arrangement will actually tension and move outwardly the sidewalls 8 of the work plank when it reaches the final fastening position, as indicated in Figures 10 and 11. In the final fastening position (Figure 5), the edge 51 is 30 firmly located within the rails 9 of the metal channel 4.
It can also be seen that the hook arrangement includes the securing port 15 for receivlng the fastener member 7. The upper surface of the hook arrangement includes stops 53 for engaging the end of the upper surface 4 of the metal 35 channel member. The hook arrangement 10 is designed to force the sidewalls 8 of the channel slightly outwardly and thus pull the upper surface 4 slightly downwardly and into WH- 9 3 9 5CA ~ ~
engagement with the upper surface of the hook arrangement (see Figures 10 and 11). This tensloning of the end of the work plank makes the hook arrangement and channel 4 f orm a smooth transition therebetween. The channel 4 is initially 5 extruded in the form of Figure 10 to provide improved support. The stop 53 also serves to locate the port 15 in alignment with the ports 5 provided in the sidewalls 8 of the work plank 2. The engaging hook portion 38 is shown in top view in Figure 9. The port 39 of the hook portion 38 10 is used for securing of a ramp 80 and can also be used for fastening a cable used to lift the work plank to a particular location on the access scaffolding. The hook portion 38 is offset to one side of the center line of the work plank and a complementary recess 61 is located to the 15 opposite side of the center line. In this way, two planks can be secured on a single transom member in an end to end manner with the hook 38 of one portion of the work plank recelved ln the recess 61 of the opposite work plank.
The sidewalls of each hook arrangement having an 20 exposed curved recess 91 for accommodating a horizontal scaffold support with flanges 47 overlying such a horizontal support and acting as a load bearing surface.
Details of the ramp and its cooperation with the hook arrangement of a work plank are shown in Figures 6 25 and 7.
Figure 7 shows first work planks 2a with a second work plank stacked thereabove. The second work plank 2b, because lt ls stacked on top of the first work planks, has the ends thereof exposed and could be a hazard as a 30 possible trip surface. For this reason, ramps 80 are used to provide a transition between the lower supporting work planks 2a and the second work plank 2b supported thereabove. The ramp 80 includes a lead-in portion 82 for insertion beneath the hook arrangement 10 and this lead-ln 35 portion passes beneath the end surface of the recess 61.
Once the lead-in portion 82 has been located, the ramp can be rotated downwardly such that the pro~ecting hook 84 Wll- 9 3 9 5CA
passes through the port 39 in the hook portion 38. This aspect is shown in Figure 6. The ramp 80 includes a recess 85 for recelving the hook arrangement 38 and lncludes a pro~ecting tongue 87 for coverlng the recess 61 ln the hook S arrangement 10. Flange 89 ls supported atop surface 45.
The double ramp 80a of Flgure 12 ls used to tle the ends of two side by side work planks together, although the ramp can be of the single design of Figure 6 for forming a transition for a single work plank. The double design of 10 Figure 12, or posslbly trlple or quadruple design, does provide a common ramp for multiple planks and also ties the planks together at the ends. The ramp also includes a sllghtly angled support edge 86 for engaging the lower work surface .
Figure 7 shows how tie 100 can engage any of the holes 14 in a lower plank and engage the channel 11 of the work plank 2b. The tie 100 includes a push in and lock foot 102 and a securlng head 104. Holes 14 provlde a host of securlng locatlons whereby tles 100 can malntaln a plank 20 stacked on lower planks ln a deslred locatlon.
The work plank, as described herein, has the advantage of good strength, hlgh durablllty and resistance to damage. Furthermore, the plank is secured in a simple mechanical manner and various parts can be salvaged in the 25 field should some work planks require repalr. The work plank is easy to assemble and the parts cooperate to simplify the manufacturlng steps, whlch can elther be carried out by a manual or automated process. The work plank provides flexlblllty wlth respect to dlfferent 30 applications and advantageously can be tied to other work planks to further improve the structural characteristics of the overall system. This tying of various work planks is seen with respect to the keying of the work planks as well as the drop-in multiple ramp which ties the ends of work 35 planks.
The angled sidewalls of the work plank have lmproved characterlstlcs wlth respect to the deflectlon of _ g _ these sldewalls under load and the sidewalls have been further improved by providing a rail and channel structure at the bottom edge thereof. The wind latch is held in place by means of a fastener, which merely passes 5 therethrough, with a latch being retained within a lower channel at the bottom edges of the work plank. If necessary, the wind latches can be secured and if not, they can merely be left in a clear position. The latches are also designed to move to a clear position when the work 10 plank is placed on a transom support. The hook arrangements inserted in the ends of the channel members cooperate to tension the end of the channel member and draw it into abutment with the upper surface of the hook arrangements. This provides a smooth transition 15 therebetween.
It has been found that the work plank with the angled sidewalls provides clearance along the sides of the work plank when work planks are placed in a side by side relationship, which is desired to simplify mechanical 20 securement of components along the sides of the work plank.
This structure also ensures that if there is some deformation of the work plank due to improper handling or loading, any outward deflection of the sidewalls still allows the work planks to be placed in a side by side 25 relationship. Thus, with age, the work planks should be capable of continuing the desired abutting side by side relationship. The clearance of the angled sidewalls also ensures that there are not large surfaces in which dirt can collect, as the point of contact of ad ~acent work planks is 30 merely along the edge thereof. The angled sidewalls also act as a camming surface during securement of work planks on scaffolding.
The upper surface 4 of the work planks 2 have a host of apertures 14 and these apertures can be used to 35 receive a fastening component for tyLng of a stacked work plank to the work plank therebelow. The fastening member may pass through a hole in the lower work plank and have a pro~ecting portion for engaging a channel or the rail of the upper work plank. In this way, the work planks can also be tied, one to the other, when the work planks are stacked .
A further feature of the invention is the fact that both the hook arrangement and the metal channel 4 have a generally open bottom configuration and allow two planks to partially nest, one within the other, when placed in opposed relAt~n~h~p This is desirable for efficient storage and transportation.
Although various preferred embodiments of the present lnvention have been described herein in detail, it will be appreciated by those skilled in the art, that variations may be made thereto without departing from the 1~ spirit o~ the invention or the scope of the appended claims .

Claims (16)

1. A work plank for work platforms, access scaffolding, walkways and the like structures comprising a metal channel having a top surface and opposed sidewalls, and wherein said opposed sidewalls are angled inwardly to oppose outward bowing of said sidewalls during loading of said work plank.

2. A work plank as claimed in claim 1 wherein said work plank at either end thereof has a hook arrangement for engaging a cylindrical support, each book arrangement being partially received in said metal channel and being mechanically secured to said metal channel.

3. A work plank as claimed in claim 1 wherein said top surface having a plurality of openings angled out of the top surface to provide traction surfaces.

4. A work plank as claimed in claim 3 wherein each hook arrangement is secured by mechanical fasteners passing through said sidewalls with said angled sidewalls providing sufficient clearance for the mechanical fasteners to project beyond said sidewalls while being located within the width of the top surface of the work plank.

5. A work plank as claimed in claim 3 wherein said plank in said sidewalls intermediate said hook arrangements includes a key hole for receiving a key used to fasten to side by side planks together.

6. A work plank as claimed in claim 5 in combination with a fastening key wherein said key hole is shaped to allow said fastening key in one orientation to be inserted therethrough and once so inserted said key can be rotated to a second orientation whereby said keyhole retains said key.

7. A work plank as claimed in claim 6 wherein said fastening key is shaped to have a gravity bias urging said fastening key to said second orientation when received in said key hole.

8. A work plank as claimed in claim 3 wherein each hook arrangement includes a port through an upper surface thereof, in combination with a ramp, said port cooperating with said ramp which is adapted to engage an end of said work plank and engage said port to thereby secure said ramp to said work plank, said ramp providing a sloped transition at the end of the plank between the lower surface of said plank and said upper surface of said plank.

9. A work plank in combination with the ramp as claimed in claim 8 wherein each hook arrangement includes two ports spaced in the width of said plank and said ramp engages each of said ports for retaining of said ramp relative to said plank.

10. A work plank as claimed in claim 8 wherein each hook arrangement, when inserted in said metal channel, is sized to tension said plank by forcing said angled sidewalls outwardly to receive the hook arrangement and drawing the upper surface of the plank into contact with an upper surface of said hook arrangement.

11. A work dank as claimed in claim 10 wherein said plank along opposed lower sides of said plank includes an upwardly opening receiving channel, each receiving channel cooperating with said fasteners to retain a lock member freely movable on said fastener between a position retaining of said hook arrangement on a cylindrical support member to a release position allowing said hook arrangement to separate from a supporting cylindrical support.

12. A scaffold access system comprising work planks supported by connected scaffolding frames, said work planks cooperating to collectively define a first raised horizontal work surface, said first raised horizontal work surface at least partially supporting thereabove additional work planks defining a second raised work surface where the work planks thereof are at an angle relative to the work planks defining the first raised work surface, each work surface comprising a metal channel having a top surface and opposed sidewalls, and wherein said opposed sidewalk are angled inwardly to oppose outward bowing of said sidewalls during loading of said work plank.

13. A system as claimed in claim 12 wherein said work plank at either end thereof having a hook arrangement for engaging a cylindrical support, each hook arrangement being partially receive in said metal channel and mechanically secured to said metal channel.

14. A system as claimed in claim 13 wherein each hook arrangement includes a port through an upper surface thereof, and wherein at least some of said work planks of said second raised horizontal surface each have a ramp associated therewith, said ports of said hook arrangements cooperating with projecting members of said ramps to secure said ramps to said work planks, said ramps providing a sloped transition at the end of the planks between said raised first horizontal surface and said raised second horizontal surface.

15. A system as claimed in claim 14 wherein at least some of said ramps are sized to provide a transition for two adjacent work planks.

16. A system as claimed in claim 12 wherein said top surface has a plurality of openings angled out of the top surface to provide traction surfaces.