WO1995006179A1

WO1995006179A1 - Safety railing system

Info

Publication number: WO1995006179A1
Application number: PCT/CA1994/000468
Authority: WO
Inventors: Theodore R. Palmer
Original assignee: Prs Industries Inc.
Priority date: 1993-08-27
Filing date: 1994-08-26
Publication date: 1995-03-02
Also published as: AU7528194A

Abstract

A safety railing (10) for installation about a roof edge. There is a vertical stanchion (20) which extends above the roof edge and a lower end which extends downwardly along the outer wall of the building (12). A middle portion of the stanchion (20) is pivotably mounted to the wall of the building (12), so that in response to a laterally directed impact at its upper end, the stanchion member pivots relative to the wall and at least a portion of the force is transmitted into the wall through the pivot connection (16).

Description

SAFETY RAILING SYSTEM

FIELD OF THE INVENTION

The present invention relates generally to safety restraints, and, more particularly, to a safety railing for temporary installation around the edge of a building roof during construction work.

BACKGROUND OF THE INVENTION

A recurring safety problem has been workers falling from the roofs of buildings which are under construction, or on which other work is being performed. Oftentimes, these accidents occur when the workers are moving about and carrying materials back and forth, and it sometimes happens that a worker will simply back over the edge of the roof while not looking.

The magnitude of this hazard has drawn the attention of several regulatory bodies, including the Occupational Safety and Health Administration in the United States, and the Department of

Occupational Safety.and Health in Canada. As a result, some form of barrier is now required around roof edges where people will be working, and various attempts have been made to comply with these requirements, with very modest success to date. For example, one approach has been to plant a series of posts on the roof and string a cord and warning flags between these; obviously, the actual restraint which is provided by the cord is minimal, and so this must be placed a considerable distance (about 6 feet) inboard from the edge of the roof, which tends to greatly reduce the available working space, and also presents a problem when it becomes necessary to work in the area outside the cord. A somewhat similar approach uses rails mounted to posts supported by base plates which rest on top of the roof; while this provides a somewhat more positive restraint, the base plates must still be set in a significant distance from the edge of the roof, which restricts the ability of personnel to work near the edge, and this also necessitates a laborious and time consuming effort to move the railings as the work progresses over the surface of the roof.

Attempts have also been made to mount a railing at the very edge of the roof, usually by mounting a plain bracket (such as a conventional leg-and-shield type arrangement) to the outer wall of the building using fasteners, and then mounting the bottom of a stanchion to this so that the stanchion extends up above the edge of the roof to support the railings. Several problems have been encountered with this approach, and these stem primarily from the inability of this arrangement to withstand any significant impact or loading on the upper railing. Current requirements call for the upper rail to be positioned about 42 inches above the edge of the roof; OSHA standards require this rail to be able to withstand the impact of a 200 pound worker, while Canadian standards call for it to be able to support a 200 pound static load in both outward and inward directions. When a conventional bracket arrangement is used, these loads translate to a pull-out force on the order of 1000 pounds or more at the wall bracket; for example, if an outwardly directed impact is received by the rail at the upper end of the stanchion, this will tend to force the lower edge of the bracket plate into the wall of the building so that this acts as a pivot point, providing a lever arm for pulling the fasteners out in much the same manner that a claw hammer provides leverage for removing a nail. Of course, if the force at the rail is inwardly directed, the upper edge of the bracket serves as the pivot point, with the same result. Moreover, because of the pivoting action, essentially the entire pull-out force must be born by whichever fastener is located nearest the outwardly moving edge of the plate, while the fasteners near the pivot edge experience relatively little of this.

The net result is that conventional railings of this type are either wholly inadequate in terms of their ability to restrain workers against potential accidents, or they must be constructed so massively as to be very difficult to install and remove, which renders them impractical for many applications. For example, those fasteners which are ordinarily favored for quick installation and removal from concrete (e.g., those sold under the trade names "Tap-Con" and "Scru-It") simply do not have the load-bearing capacity necessary to withstand the pull-out loads to which they would be subjected in an conventional bracket arrangement, and so fasteners of a heavier and usually more permanent nature

(e.g., lag bolts) must be employed, which simply renders this approach impractical for most temporary installations.

Accordingly, there exists a need for a railing system which can be mounted right at the edge of a roof so as to make the maximum space available for work, and so as to also eliminate the need to move this as the work progresses. Furthermore, there exists a need for a railing system of this type which is easily installed and removed, so that this can be efficiently used on a temporary basis during building construction. Still further, there is a need for a railing system of this type which is economical to fabricate, and which takes advantage of readily available railing members, such as standard length 2x4s. SUMMARY OF THE INVENTION

The present invention has solved the problems cited above. This is a safety railing for installation about a roof edge of a building, comprising broadly a vertically aligned extension member having an upper end for extending above the roof edge and a lower end, the upper end being configured for mounting to a railing member which extends along the roof edge, the mounting member configured for attachment to an outer wall of the building, and pivot means for interconnecting the mounting member and a middle portion of the stanchion member, so that in response to application of a laterally directed force to the railing member mounted to the upper end of the stanchion member, the lower end pivots relative to the wall of the building and at least a portion of the force is transmitted into the mounting member on the wall via the pivot means.

The mounting means may comprise a bracket member configured for flush mounting against an outer surface of the wall. The pivot means, in turn, may comprise means for pivotably mounting the middle portion of the stanchion to the bracket member so that in response to application of an outwardly directed force to the railing member mounted to the upper end of the stanchion member, the lower end of the stanchion member pivots inwardly to apply an inward force against the wall and the middle portion applies an outward force to the bracket member in a combined pull-out and shear direction. There may also be a first stopper assembly mounted to the stanchion member below the pivot means and extending inwardly so as to abut the wall of the building, and a second stopper assembly mounted to the stanchion member above the pivot means and extending inwardly so as to abut the wall. The stopper assemblies may each be configured for selective adjustment of the distances which they extend from the stanchion member, so as to permit adjustment of the stanchion member into vertical alignment. In a first embodiment, the means for pivotally mounting the middle portion of the stanchion to the bracket member may comprise first and second sleeve members mounted to the bracket member in axial alignment and spaced apart so as to form a gap intermediate the sleeve members, and a sleeve member mounted to the stanchion member so that an axis thereof extends transversely to the stanchion member and being sized to be received intermediate the spaced apart sleeve members on the bracket member in axial alignment therewith, and a pivot pin member configured to be passed axially through the sleeve members so as to retain the stanchion member in pivoting engagement with the bracket member. The pivot pin member may comprise a bolt which is configured to pass through the first sleeve member on the bracket and having a threaded end for engaging an internally threaded portion formed on the second sleeve member. In a second embodiment, the means for pivotally mounting the middle portion of the stanchion to the bracket member comprises a pivoting link member for pivoting outwardly at an angle to the bracket member in response to the force which is supplied to the railing member, so that the force is transmitted to the bracket member in the combined pull-out and shear direction. There may also be hinge means for connecting the pivoting link member to the bracket member so that the link member is pivotable about an axis which extends in a horizontal direction. Also, there is an attachment member mounted to the middle portion of the stanchion member for detachably mounting the stanchion member to an outer end of the pivoting link member. The attachment member may comprise a laterally extending pivot pin which is received and supported in a hook portion at the outer end of the pivoting link member.

In another embodiment, the mounting member for attachment to the wall of a building may be a clamp member for engaging a parapet of the wall, and the pivot means for interconnecting the mounting member and the middle portion of the stanchion member may comprise a flexible fork assembly having first and second independently flexible support portions, a clamp member being mounted to the first support portion and the stanchion member being mounted to the second support portion, so that the second support portion flexes in response to the force applied to the railing member mounted to the stanchion member, while the first support portion having a clamp member mounted thereon remains stationary in relation to the wall. Preferably, the support portions of the fork assembly may comprise first and second generally parallel, elongate leg members having inner ends which are joined together and outer ends which are free to flex independently of one another, the stanchion member and a first jaw portion of the clamp member being mounted to the outer ends of the second and first leg members, respectively. Each of the leg members may be a tubular steel member. The second jaw portion of the clamp assembly is mounted to the inner ends of the leg members in opposition to the first jaw portion so that a gap is formed intermediate the jaw portions for receiving the wall parapet. Means are preferably provided for permitting adjustment of the position of the first jaw portion of the clamp assembly along the second leg member so as to adjust this gap, and there is preferably a screw drive for tightening the clamp assembly. Means are preferably provided for permitting adjustment of the position of the stanchion along its leg member as well. Means for permitting adjustment along the leg members may comprise collar members mounted on the leg members for sliding movement. There are also preferably means for selectively locking the collar members at selected positions along the leg members, and this may comprise a plurality of socket portions formed at spaced apart locations along each leg member, and locking plungers mounted on each collar member for selectively engaging the socket portions at selected positions along the leg members.

Objects and advantages of the invention not clear from the above will be understood by a reading of the detailed description and a review of the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the railing system of the present invention, this showing the system mounted at the roof edge of a building, with 2x4 railing members extending between the stanchions;

FIG. 2 is a perspective view of the stanchion and mounting bracket assemblies of the railing system of FIG. 1;

FIG. 3 is a side elevational view of a portion of the railing system of FIG. 1, showing this being installed on the roof edge of the building, the building being shown partly in cross section;

FIG. 4 is a side elevational view similar to that of FIG. 3, showing the railing system having been installed and properly adjusted;

FIG. 5 is a side elevational view similar to that of FIGS. 3-4, showing an outwardly directed force being applied to the upper railing of the system, and how the system responds by the swinging link pivoting outwardly from the wall bracket so that a combined loading is applied to the fasteners which hold this to the building; FIG. 6 is a side elevational view of the upper end portion of the stanchion assembly shown above, this showing the ends of 2x4 railing members positioned in this in εide-by-εide relationship, as opposed to being overlapped on top of one another as shown in FIGS. 4-5; FIG. 7 is a side elevational view of a second embodiment of the railing system of the present invention, wherein the pivoting attachment to the wall of the building is provided by a simplified bolt-and-sleeve arrangement; FIG. 8 is an exploded view of the bolt-and- sleeve pivot attachment of the system shown in FIG. 7;

FIG. 9 is a side elevational view of another embodiment of railing system in accordance with the present invention, wherein the system is mounted to the upper edge of a wall by a clamp, and the pivot connection is provided by a split fork assembly which decouples motion of the railing from the clamp so as to avoid prying the latter off the parapet; and

FIG. 10 is a prospective view of the fork assembly of the system shown in FIG. 9, showing the mounting attachments for the railing stanchion and the parapet clamp. DETAILED DESCRIPTION

FIG. 1 provides an overview of the railing system 10, this being mounted to the roof edge of a building 12. The railing system comprises a series of spaced-apart support assemblies 14, each of these being made up of a swinging link bracket assembly 16 which is mounted to the vertical outer wall 18, and a stanchion assembly 20 which is mounted to the bracket assembly and extends upwardly from this above the edge of the roof 22. At the upper end of each stanchion assembly there is a square loop portion 24, and there is a second square loop portion 26 positioned a short distance down the stanchion below this. These square loop portions provide receptacles through which the ends of rail members 28 extend; as can be seen in FIG. 1, the end of a first rail member is received in each loop portion, and then the end of the next rail member in the series is also received in this loop so as to.overlap against the end of the first member. Thus, those rail members which are received and supported in the upper loop portions 24 form a continuous upper rail 30, while those which are received in the lower loop portions 26 form a continuous lower rail 32. It has been found that standard 10-foot long wooden 2x4s provide eminently suitable rail members for this system, and are well up to bearing the necessary impact loads.

Having provided an overview of the railing system of the present invention, its components and their operation will now be described in greater detail.

FIG. 2 illustrates the two primary support components of the system, the stanchion assembly 20 and the swinging link bracket assembly 16. The primary structural component of the stanchion assembly 20 is an elongate bar member 34, this preferably being a tubular steel member; a 6-foot length of Ik inch square steel tubing has been found eminently suitable for this purpose. As was noted above, an upper loop portion 24 is mounted at the upper end of the stanchion, and a lower loop portion 26 is mounted a short way below this. Each of these loop portions is preferably formed of a piece of flat bar stock bent to form a square receiving area 36, 38, and welded to the bar member 34 at the desired locations; it has been found desirable to position the lower loop portion (and hence the lower rail) about 19 inches below the upper.

Each of the square receiving areas 36, 38 is sized so that the ends of two rail members can be received in this, either in side-by-side relationship or overlapped on top of one another; for conventional 2x4ε, 3 3/4 inch square receiving areas have been found appropriate. The upper and side legs of each of these square loop portions are pierced by upper and side nail openings 40, 42, the use of which will be discussed below.

Then, generally toward the lower end of the stanchion, there is a pivot pin 44 which is mounted to the bar member 34 so as to extend transversely across this. In order to obtain the desired height of the upper rail above the roof edge (i.e., about 42 inches), it has been found desirable for many applications to mount the pivot pin 44 about 50^ inches below the upper end of a 72-inch stanchion. The pivot pin may be provided by a ij-inch steel pin approximately 4 inches long, and this is preferably mounted to the same, inboard face of the square bar member 34 as the loop portions, so that the rail members are supported against the inboard side of the bar member (i.e., toward the working area) when the assembly is in place. A first adjustable stopper assembly 46 is mounted a relatively short distance (e.g., about 6 inches) above the horizontally extending pivot pin, and this is made up of a base nut 50 which is welded to the inboard face of the bar member, and a foot portion 52 having a threaded shaft which is engaged by the base nut so that the distance by which the foot portion extends inwardly from the bar member 34 is selectively adjustable. A hole (not shown) is formed in the inboard wall of bar member 34 for the shaft of the foot portion to extend through in order to permit a greater range of adjustment, and an elastomeric friction pad 54 is mounted on the outer end of the foot portion so as to enhance the frictional engagement of the stopper assembly with the outer wall of the building. The lower stopper assembly 48, in turn, is mounted at or near the very lower end of bar me ber 34 (about 21-22 inches below pivot pin 44 on a 6-foot long stanchion assembly), and this similarly comprises a base nut 56, adjustable foot portion 58, and friction pad 60. As will become apparent from the description provided below, these stopper assemblies serve to provide the correct vertical alignment of the stanchion assembly, and also make it impossible for this to be accidentally dislodged from the bracket assembly once the system has been properly installed and adjusted.

Turning now to the bracket assembly 16, it will be seen in FIG. 2 that this comprises generally a base plate portion 62 and a swinging link portion 64. The swinging link portion is made up of first and second parallel hook portions 66, 68, these having U-shaped enclosed ends which together define an area for receiving the pivot pin 44 of the stanchion assembly, and supporting this in pivoting relationship; hook portions providing a receiving channel about 2 inches long and about 3/8 inch wide have been found suitable for use with a stanchion asεembly having the exemplary dimensions described above. The two hook portions 66, 68 are interconnected by the pin of a hinge 70 so that these move together in unison. The central loop 72 of the hinge, in turn, is mounted to the base plate portion of the assembly. This base plate portion is a flat, preferably rectangular member which is configured to abut the outer wall of the building. This is pierced by bores 74 above and below the hinge loop for the fasteners to extend through. A suitable spacing for these fastener bores has been found to be about 3 inches, centered on the horizontal hinge of the assembly, with a lower portion of the base plate extending about 3^ inches below the lower bore to give an overall plate length of about 7 inches. First and second upstanding, parallel ears 78 are mounted at the lower end of the base plate, and these define a gap for receiving the bar member 34 of the stanchion assembly and fitting closely adjacent the sidewalls of this; these ears 78 serve to steady the stanchion assemblies against side-to-side "tipping" motion before the rail members have been installed therein.

The installation of these assemblies and their adjustment will now be described with reference to FIGS. 3-4. The building structure 12 shown in FIG. 3 represents a typical wooden construction, in which there are wooden wall studs 80, 82 covered by an exterior facia 84, and these provide anchors for the fasteners of the railing system 10. However, it will be understood that the mounting shown here is equally applicable to concrete block structures, in which there is a concrete bond beam at the upper edge of the wall, as well as to those buildings which are constructed with a poured wall which extends all the way to the roof edge. To install the railing system, the bracket assembly 16 is positioned a sufficient distance below the upper edge 86 of the exterior facia that the upper stopper assembly 46 will be positioned to abut the facia when the stanchion is received in the bracket assembly. The fastener bores are placed in proper vertical alignment, and then fasteners 88 are driven through these into the underlying wall structure. Since the configuration of the railing system of the present invention is such that the fasteners do not have to resist the tremendous pull-out forces which are experienced when using the conventional railing systems discussed above, these can be fasteners of the type which are easily and quickly installed and then removed to provide a temporary installation, such as the Tap-Con^ or Scru-It^ fasteners noted above.

The bracket assembly having been installed, the next step is to set the stanchion assembly in this. This is done by pivoting the swinging link portion 64 of the bracket assembly outwardly so that the gap between the tips of the hook portions 66, 68 and the hinge 70 extends laterally to receive the pivot pin on the stanchion asεembly. Aε may be seen in FIG. 3, the hook portions of the bracket assembly are preferably sized so that this gap is only just large enough to let the pivot pin 44 pass through, so as to further reduce the chances of accidental dislodgment of the stanchion from the bracket assembly. As the pivot pin is set in the hook portion of the bracket assembly, the lower portion of the bar member 34 is simultaneously received in the gap between the upstanding ear portions 78 these steady the stanchion assembly against side-to-side rocking. The stanchion assembly is then lowered until the pivot pin rests in the closed ends of the hooks 66, 68 and the stanchion is suspended therein, and the foot portions of the stopper assemblies 46, 48 are extended outwardly from bar member 34 until the stanchion is aligned in a vertical direction. Further outward adjustment of the stopper assemblies is made, if necessary, until the pivot pin 44 has pulled the swinging link portion of the bracket assembly outwardly a short distance to the point where the receiving areas in the hook portions no longer extend in a vertical direction, as this is shown in FIG. 4.

It will be understood that in this position it is no longer possible for the pivot pin 44 to become accidentally dislodged from the hook portions of the bracket assembly, whether by lifting or pivoting of the stanchion assembly, being that it is not possible to move the pin in a vertical direction within the receiving areas of the hooks.

Having completed the installation and alignment of the bracket and stanchion assemblies, the next step is to install the rail members 28, and this is done by inserting their ends in the receiving areas of the loop portions 24, 26 (24 only shown in FIGS. 3-4) . These are overlapped in the manner previously described, and a suitable nail 90 is then inserted through the appropriate nail opening (top opening 40, in the arrangement shown in FIG. 4) and hammered into the overlapped ends of the rail members so as to lock these together and prevent them from sliding out of the loop portion. This is done at each of the spaced- apart support assemblies until the continuous rail is completed, and the same is done for the lower rail as well. The installation is then complete and ready for work to commence.

FIG. 5 illustrates the operation of the railing system 10, as this would prevent a person from moving outwardly over the edge of the roof. As can be seen, the force of the outwardly directed load or impact is represented in FIG. 5 by arrow 96. As this is applied to the upper railing, this force is transmitted through the railing to the upper end of the bar member 34.

This outward movement of the upper end of the bar member causes the stanchion assembly to pivot about pivot pin 44, forcing the lower stopper assembly 48 against the exterior facia 84, and lifting the upper stopper assembly 46 away from this. Simultaneously, as the bar member 34 pivots outwardly about the pivot point which is provided by the lower stopper assembly 48, pivot pin 44 pulls outwardly on the swinging link portion of the bracket asεembly, cauεing the hook portions thereof to pivot outwardly.

In this position, with the hook portions of the bracket assembly extending at an angle from the base plate, and the outward force being transmitted from the stanchion assembly to the bracket assembly in this direction, the fasteners 88 are subjected to a "combined" loading. That is, they are not subjected to a pure pull-out force, nor to a pure shear force, but instead they are subjected to a force which combines elements of both pull-out and shear. As a result, because the asteners' capacity with respect to both of these forces is being employed, the effective load-bearing ability of each fastener is greatly increased (relative to that for pure pull-out or shear), to the point of being nearly doubled. Also, because the pivot point is now provided by the lower stopper assembly 48, instead of the lower edge of the bracket plate, the ratio of the two lever arms is greatly reduced, and the magnitude of the pull-out force is therefore much smaller. Furthermore, because the force is transmitted to the base plate of the bracket assembly at the midpoint between the two fasteners 88, the load is equally shared by these, rather than one or the other of the fasteners having to bear most of this alone. As waε noted above, these factors render the mounting of the railing system of the present invention much safer and more secure than conventional railing systems, and also make it possible to use easily installed temporary fastenerε which would not be able to withstand the severe loading which would be encountered when using a conventional bracket arrangement.

As was also noted above, the loop portions 24, 26 of the stanchion assemblies are configured so that their receiving areas are able to accommodate the ends of railing members (such as 2x4ε) which are laid on top of one another, so that the railing members themselves rest horizontally, or these ends may be positioned in side-by-side relationship so that the railing members stand on edge. FIG. 6 shows this latter arrangement, with the two railing members 28a set on edge in the loop portion 24, and then a nail 98 is inserted through the side nail opening and driven into the boards to hold these in place. The embodiment discussed above provides the railing system of the present invention with the many advantages which have been described. In some cases, however, it may be desirable to employ a somewhat simplified approach which provides these advantages in large measure, but at a reduced cost. An exemplary embodiment which utilizes such a simplified approach is illustrated in FIGS. 7-8. As can be seen, this system 100 is generally similar to that described above in that it includes a vertical stanchion aεεembly 102 having upper, and lower loops 104, 106 for receiving the railing memberε. Alεo, the lower section of the εtanchion iε again provided with upper and lower adjustable stopper assemblies 108, 110 which bear against the wall 114 of the building 116. As with the previously described embodiment, the stopper assemblies vertically flank a pivotable mounting assembly 112, but this is relatively simplified from the swinging link arrangement described above, thereby reducing production costs while retaining a major portion of the advantages provided by the more complex construction.

The fixed member of the mounting asεembly 112 is bracket assembly 118, and this is provided with a base plate 120 which is mounted to the wall surface by means of bolts which extend through bores 122. First and second barrel sleeves 124, 126 are welded or otherwise mounted to the outer surface of the base plate with their bores aligned coaxially to receive the shank of a bolt 128. A nut 130 having internal threads is mounted to the outer end of the second barrel sleeve 126, for engaging the threads on the end of the bolt after this has been extended through the two sleeves; alternatively, the second sleeve may itself be internally threaded.

The stanchion 102, in turn, is provided with a corresponding barrel sleeve 132 which is mounted to its inner surface and which is sized to fit closely between the two fixed sleeves mounted to the base plat.e. Thus, the stanchion can be slid into position so that the sleeves 124, 126 and 132 are aligned in the manner shown in FIG. 8, and then the bolt 128 passed through these and tightened so as to secure the assembly together.

Thus assembled, the stanchion assembly pivots freely about the axis of a bolt 128 in response to forces directed outwardly and inwardly against the railing members supported by the upper end of the stanchion. The corresponding forces at the lower end of the stanchion are directed into the wall of the building by the stopper assemblies, and the pivoting action ensures that the fasteners holding the bracket assembly to the wall are loaded in combined tension and shear. Also (as with the embodiment described above), the increased length of the lever arm from the pivot assembly to the engaged stopper, relative to that of the arm from the upper end of the stanchion to the pivot point, serves to minimize the pull-out force which is experienced by the mounting assembly. FIGS. 9-10 show an embodiment of the present invention which is particularly adapted for mounting to the upper edge or "parapet" of a wall. As was noted in the background discussion above, many standards (as well as real world incidents) require that the railing system be able to withstand a significant inward impact, in addition to a more typical outward loading. Building parapets provide a very convenient attachment point for railing systems, since these can readily be engaged using large clamps. However, where such clamps have been employed in the past, inwardly directed forces on the railings have tended to pry or pop the clamps off of the parapet, in part because of the lever arm provided by the span of the clamp acrosε the top of the wall. This problem is overcome in the system 140 by means of a forked mounting bracket which partially decouples the stanchion from the mounting clamp so as to prevent direct transmission of force to the latter.

As is shown in FIG. 9, the stanchion assembly 142 and railing loops are εubstantially identical to the corresponding members described above. Also, the lower section of the stanchion is again provided with upper and lower adjustable stopper assemblies 148, 150. However, in this embodiment, the pivotable mounting is not provided by a wall attachment between these, but rather by a bifurcated clamp assembly 152 which engages a middle portion of the stanchion and extends from this for mounting to the upper edge of the parapet 154.

FIG. 10 shows the bifurcated clamp assembly 152 in greater detail. As can be seen, this is made up generally of first and second support legs 156, 158 which extend closely parallel to one another. Support members 156, 158 are formed of box-section steel tube, although any suitable, somewhat flexible material may be employed. The parallel supports are joined together at one end, where they are welded to the εideε of a vertically extending support member 159 which fits between them. For additional strength, the two supports are joined at a second point near this end, by welding to a spacer 162, but from here to the other end there are no additional connections between the two members. For reasons which will be discussed below, the material of which the two support legs are formed is resilient and readily deflected under a load, and this arrangement consequently permits the two members to flex upwardly and downwardly independently at their outer ends. Aε is shown in FIG. 9, the free ends of the two support legs are configured to extend across and outwardly from the top of the building parapet 154. On the first leg 156 there is a bracket subassembly 160 for engaging and supporting the vertically extending stanchion. This bracket subassembly includes a sleeve portion 162 which fits around the associated support leg 156 for sliding movement thereon, and a pair of ears 164 which extend outwardly from the sleeve for attachment to the stanchion; the stanchion fits between the two ears, and a bolt (not shown) or other suitable member is passed through these to lock the stanchion in place. As will be described in greater detail below, the bracket subassembly is also provided with a locking mechanism 166 which permits adjustment of the location of the subassembly along the support leg so as to accommodate parapets of various widths.

The other leg 158 supports an adjustable clamping subassembly 170. As with the bracket subassembly, this is provided with a sliding sleeve 172 which engages the support leg. In this case, a downwardly extending plate 174 iε mounted to the εleeve to support the clamp drive 176. The drive includes a threaded block 178 which is welded to the end of the support plate 174, and a screw member 180 which passes through this. A "T" handle 182 is mounted to one end of the screw member to facilitate manual rotation of the drive, and a first clamping plate 184 is mounted to the other end of the screw member for engaging the outer surface of the parapet. An anti-rotation strap 186 extends upwardly to a second sliding sleeve 188 on the support leg 158 to hold the plate from rotating with the drive screw.

The first clamping plate 184 is arranged in opposition to a second clamping plate 190 which is mounted to the lower end of support member 159 for engaging the inner surface of the parapet; accordingly, the two plates define a gap for receiving the upper edge of the parapet. The initial width of this gap can be adjusted by releasing the clamping subassembly's locking mechanism 192 so that the subassembly can be slid along the support leg 158. As is shown in

FIG. 10, the locking mechanism is provided with a spring-loaded plunger 194 which can be manually withdrawn from one of a series of sockets 196 in the upper surface of the support leg so as to permit the entire subassembly 170 to be slid to the desired location, where the plunger is then released that it enters another of the sockets to lock the subassembly in place. After initial adjustment of the gap, the clamping assembly is tightened using handle 182 so aε to firmly mount the assembly 152 to the parapet.

With the syεtem mounted on a parapet as shown in FIG. 9, inwardly directed loads experienced at the upper end of the stanchion are translated into upward flexing of the stanchion support leg 156, as is illustrated by the arrow in FIG. 10, while the clamp support leg remains stationary. This relative motion acts as something of a shock absorber to absorb the impact force, rather than transmitting this directly to the clamping subassembly. Also, by positioning the attachment point between the two legs at a location which is generally over the middle of the parapet, the mechanical advantage offered to the prying force is effectively minimized.

Having described the invention in its preferred embodiments, it will be clear that changes and modifications may be made without departing from the spirit of the invention. For example, a magnet or adhesive may be used to mount the base plates of the bracket assemblies to exterior walls where penetrating faεtenerε or welding are not feasible. It is therefore not intended that the words used to describe the invention or the drawings illustrating the same be limiting on the invention. Rather, it is intended that the invention only be limited by the scope of the appended claims.

Claims

What Is Claimed is:

1. A safety railing for installation about a roof edge of a building, said safety railing comprising: a vertically elongate stanchion member having an upper end for extending above said roof edge and a lower end, said upper end of said stanchion member being configured for mounting to a railing member which extends along said roof edge; a mounting member configured for attachment to an outer wall of said building; and pivot means for interconnecting said mounting member and a middle portion of said stanchion member, so that in response to application of a laterally directed force to a said railing member mounted to said upper end of said stanchion member, said lower end of said .stanchion member pivots relative to said wall of said building and at least a portion of said force is transmitted into said mounting member on said wall via said pivot means.

2. The safety railing of claim 1, wherein said mounting member comprises: a bracket member configured for flush mounting against an outer surface of said wall.

3. The safety railing of claim 2, wherein said pivot means comprises: means for pivotably mounting said middle portion of said stanchion to said bracket member so that in response to application of an outwardly directed force to said railing member mounted to said upper end of said stanchion member, said lower end of said stanchion member pivots inwardly to apply an inward force against said wall and said middle portion applies an outward force to said bracket member in a combined pull-out and shear direction.

4. The safety railing of claim 3, further comprising: a first stopper assembly mounted to said stanchion member below said pivot means and extending inwardly so as to abut said wall of said building; and a second stopper assembly mounted to said εtanchion member above said pivot means and extending inwardly so aε to abut said wall.

5. The safety railing of claim 4, wherein said stopper aεεemblieε each being configured for selective adjustment of the distance which said aεεemblieε extend from said εtanchion member, εo as to permit selective adjustment of said stanchion member to a vertical alignment.

6. The safety railing of claim 3, wherein said means for pivotably mounting said middle portion of said stanchion to said bracket member comprises: firεt and second sleeve members mounted to said bracket member in axial alignment and spaced apart so as to form a gap intermediate said sleeve members; a sleeve member mounted to said stanchion member so that an axis thereof extends transversely to said stanchion member and being sized to be received intermediate said spaced apart sleeve members on said bracket member in axial alignment therewith; and a pivot pin member configured to be passed axially through said sleeve members so as to retain said stanchion member in pivoting engagement with said bracket member.

7. The safety railing of claim 6, wherein said pivot pin member comprises: a bolt configured to pass through said first sleeve member on said bracket member and having a threaded end for engaging an internally threaded portion formed on said second sleeve member.

8. The safety railing of claim 3, wherein said means for pivotably mounting said middle portion of said stanchion to said bracket member comprises: a pivoting link member for pivoting outwardly at an angle to εaid bracket member in response to εaid force applied to said railing member, so that said force is transmitted to said bracket member in said combined pull-out and shear direction.

9. The safety railing of claim 8, further comprising hinge means connecting said pivoting link member to εaid bracket member εo that εaid link member is pivotable about an axis which extends in a horizontal direction.

10. The safety railing of claim 9, further comprising an attachment member mounted to said middle portion of said stanchion member for detachably mounting said stanchion member to an outer end of said pivoting link member.

11. The safety railing of claim 10, wherein said attachment member comprises a pivot pin mounted to said stanchion member so as to extend laterally thereto.

12. The safety railing of claim 11, wherein said outer end of said pivoting link member comprises at least one hook portion configured to receive and support said pivot pin so as to permit said pivot pin to pivot about an axis which extends in a horizontal direction parallel to said axis of said hinge means on εaid bracket member.

13. The safety railing of claim 12, further comprising: a first stopper assembly mounted to said stanchion member below εaid pivot pin and extending inwardly so as to abut said wall of said building; and a second stopper assembly mounted to εaid εtanchion member above εaid pivot pin and extending inwardly εo as to abut said wall of said building; said stopper assemblies each being configured for selective adjustment of the distance which εaid assemblies extend from said stanchion member, εo as to permit selective adjustment of said stanchion member to a vertical alignment, and to an outwardly displaced position which eliminates possible accidental dislodgement of said pivot pin from said hook portion due to movement of said stanchion member.

14. The safety railing of claim 1, further comprising a loop member mounted to said upper end of said stanchion member, said loop member being configured to receive overlapped ends of first and second said railing members.

15. The safety railing of claim 14, wherein said railing members are wooden boards, and said loop member is provided with an opening for extending a nail through said loop member and into said overlapped ends of said wooden rail members so as to lock said ends of εaid rail members together in said loop member.

16. The safety railing of claim 1, wherein said mounting member configured for attachment to said wall of said building compriseε: a clamp member for engaging a parapet of said wall, said clamp member having first and second jaw portions for engaging said parapet.

17. The safety railing of claim 16, wherein said pivot means for interconnecting said mounting member and said middle portion of said stanchion member comprises: a flexible fork assembly having first and second independently flexible support portions; said clamp member being mounted to εaid first support portion and said stanchion member being mounted tts said s-econd support p rtion, so that said second support portion flexes in response to said force applied to said railing member while said first support portion having said clamp member mounted thereon remains stationary in relation to said wall.

18. The safety railing of claim 17, wherein said support portions of said fork assembly comprise: first and second generally parallel, elongate leg members having inner ends which are joined together and outer ends which are free to flex independently of one another, said εtanchion member and εaid first jaw portion of said clamp member being mounted to said outer ends of said second and first leg members, respectively.

19. The safety railing of claim 18, wherein each said leg member is a tubular steel member.

20. The safety railing of claim 18, wherein εaid second jaw portion of εaid clamp aεεembly is mounted to said inner ends of εaid leg members in opposition to said first, jaw portion so that a gap is formed intermediate said jaw portions for receiving said wall parapet.

21. The safety railing of claim 20, wherein said fork assembly further comprises: means for permitting adjustment of the position of said first jaw portion of said clamp assembly along said first leg member so as to adjust said gap intermediate said first and second jaw portions.

22. The safety railing of claim 21, wherein said means for permitting adjustment of said position of said first jaw portion comprises: a collar member mounted on said first leg member for sliding movement along said leg member; and means for mounting said first jaw portion to said collar member.

23. The safety railing of claim 22, wherein said means for permitting adjustment of εaid position of εaid first jaw portion further comprises: means for selectively locking said collar member at selected positions along said first leg member.

24. The safety railing of claim 23, wherein said means for locking said first jaw portion at selected positions comprises: a plurality of socket portions formed at spaced apart locations along εaid first leg member; and a locking plunger mounted on said collar member for selecively engaging said socket portionε at said selected positions along said leg member.

25. The safety railing of claim 23, wherein said fork assembly further compriseε: means for permitting adjustment of said position of said stanchion member on said second leg member.

26. The safety railing of claim 25, wherein said means for permitting adjustment of said position of said stanchion member compriseε: a collar member mounted on said second leg member for sliding movement along said second leg member; means for mounting said stanchion member to said collar member on said second leg member; and means for selectively locking said collar member at selected poεitions along εaid second leg member.

27. The safety railing of claim 21, wherein said first jaw portion of said clamp assembly comprises: an engagement member for abutting an outer surface of said wall parapet; and a drive screw for selectively tightening said engagement member against said wall surface.