US20130087669A1

US20130087669A1 - Roof Safety Anchor

Info

Publication number: US20130087669A1
Application number: US13/269,754
Authority: US
Inventors: Vincent P. Daddio
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-10-10
Filing date: 2011-10-10
Publication date: 2013-04-11

Abstract

A dual-purpose roof safety anchor includes an elongated base plate and a flange connected to the mid-section of the base plate and extending outwardly therefrom. A hole in the flange can be engaged by a workman's safety line. A series of fastening holes are formed in the base plate, including at least three such holes on each side of the flange, and aligned with the central longitudinal axis of the base plate; these three holes can be used to fasten the base plate to a wooden rafter of a wooden roof structure. At least two additional holes are formed on each side of the flange on opposing sides of the central longitudinal axis of the base plate. These two additional holes, along with at least one of the centrally-aligned holes, can be used to fasten the base plate to a support purlin of a metal roof structure.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates generally to safety equipment for preventing injury to workmen while working on sloped roofs, and more particularly, to a dual-purpose safety anchor adapted for use on both metal roof structures and wooden roof structures.
2. Description of the Relevant Art
Working on steeply sloped roofs is obviously dangerous work. According to data from the U.S. Bureau of Labor Statistics, about 40 persons are killed each year as a result of falls from residential roofs. The Division of Occupational Safety and Health for the California Department of Industrial Relations has stated that falls are the most common of all accidents associated with roofing, and that such falls are also likely to cause the most serious injuries. They estimate that about 30 percent of all injuries to roofers are sustained as a result of falls or slips. Apart from loss of life or serious injury sustained by such workers themselves, contractors also suffer the consequences of losing the use of experienced personnel, who are often a contractor's most valuable asset.
The U.S. Occupational Safety and Health Administration (OSHA) imposes certain safety standards in the construction industry, including standards for workers engaged in residential construction. Roof workers generally must be protected by conventional fall protection (i.e., guardrail systems, safety net systems, or personal fall arrest systems), under 29 CFR 1926.501(b)(13). OSHA has recently noted that there continue to be high numbers of fall-related fatalities in residential construction, and OSHA statistics show that the lack of fall protection still remains the number one safety violation in the roofing industry.
Personal fall-arrest systems are available for protecting roofing workers from falls. OSHA requires personal fall arrest systems to include body harnesses equipped with safety lanyards and locking snap hooks. OSHA also promulgates standards for anchoring points, or “roof anchors”, used to support such personal fall arrest systems.
Prior art roof anchors are available that require installation over the ridge of the roof; for example, in U.S. Pat. No. 4,249,173 (Glynn, et al.), a roof attachment is disclosed for attachment to the peak of a wooden roof and to which a safety line can be clipped. However, the roof attachment disclosed by Glynn must be attached to the ridge, or highest point, on the wooden roof structure. On the other hand, it is sometimes desired to create an anchor point at a lower point, below the ridge of the roof; in that case, the roof attachment disclosed in U.S. Pat. No. 4,249,173 may not be used.
In addition, many commercial, and some residential, buildings make use of metal roofs using corrugated metal roof panels secured over supporting metal purlins. It is often the case that there is no underlying support purlin at the ridge of the roof; rather, the support purlins may be located on either side of the ridge, and perhaps one foot or more away from the ridge. In that case, an anchor adapted to engage the ridge of the roof may not be compatible with the underlying metal roof.
In addition, wooden roofs and metal roofs differ significantly from each other in regard to the configuration of the underlying supporting members. In wooden roofs, the underlying support rafters generally slope upwardly from the eaves to the ridge, and extend perpendicular to the ridge. In contrast, in the case of metal roofs, the underlying support purlins generally extend parallel to the ridge. Thus, a safety anchor designed for use with a wooden roof may not be compatible for use with a metal roof, and vice versa.
Accordingly, it is an object of the present invention to provide a roof safety anchor which can be secured upon a sloped roof structure either near the ridge of the roof or at a lower point.
It is another object of the present invention to provide such a roof safety anchor that can be used with either sloped wooden roofs or sloped metal roofs without modification.
It is a further object of the present invention to provide such a roof safety anchor that is of simple and inexpensive construction, and which may be installed easily and quickly upon a roof.
These and other objects of the invention will become more apparent to those skilled in the art as the description of the present invention proceeds.

SUMMARY OF THE INVENTION

Briefly described, and in accordance with a preferred embodiment thereof, the present invention relates to a roof safety anchor that includes an elongated base plate and a flange. The base plate is substantially planar and extends along a central longitudinal axis between first and second opposing ends. The flange is connected to the base plate substantially midway between its first and second ends, and extends substantially perpendicular to the base plate, bisecting the base plate into a first half and a second half. The flange has a hole formed therein for being engaged by a hook/clip of a workman's safety lanyard.
The first half of the base plate has first, second and third fastening holes formed therein substantially aligned with each other along the central longitudinal axis of the base plate. The first such fastening hole lies closest to the first end of the base plate, while the third fastening hole lies closest to the flange. The second fastening hole lies between the first and third fastening holes. These three fastening holes are generally all used when the safety anchor is secured to a wooden rafter of a wooden roof structure.
The first half of the base plate further includes fourth and fifth fastening holes which lie on opposing sides of the central longitudinal axis of the base plate. The fourth and fifth fastening holes lie no closer to the first end of the base plate than does the first fastening hole; likewise, the fourth and fifth fastening holes lie no closer to the flange than does the third fastening hole. When the safety anchor is secured to a metal roof, these fourth and fifth fastening holes are used, along with at least one of the first and third fastening holes.
The second half of the base plate is essentially a mirror image of the first half. The second half of the base plate includes sixth, seventh and eighth fastening holes formed therein substantially aligned with each other along the central longitudinal axis of the base plate. The sixth fastening hole lies closest to the second end of the base plate, while the eighth fastening hole lies closest to the flange. The seventh fastening hole lies between the sixth and eighth fastening holes. Once again, these three fastening holes are generally all used when the safety anchor is secured to a wooden rafter of a wooden roof structure.
The second half of the base plate further includes ninth and tenth fastening holes which lie on opposing sides of the central longitudinal axis of the base plate. The ninth and tenth fastening holes lie no closer to the second end of the base plate than does the sixth fastening hole; likewise, the ninth and tenth fastening holes lie no closer to the flange than does the eighth fastening hole. When the safety anchor is secured to a metal roof, these ninth and tenth fastening holes are used, along with at least one of the sixth and eighth fastening holes.
Preferably, the second, fourth and fifth fastening holes are substantially aligned with each other along a first lateral axis that extends substantially perpendicular to the central longitudinal axis of said base plate. Likewise, in the preferred embodiment, the seventh, ninth and tenth fastening holes are substantially aligned with each other along a second lateral axis that extends substantially perpendicular to the central longitudinal axis of said base plate.
When the roof safety anchor is installed on a wooden roof structure, first, second, and third screws (or lag bolts) extend through the first, second, and third fastening holes, respectively, through a wooden sheathing panel, and into a wooden rafter. Similarly, fourth, fifth, and sixth screws extend through the sixth, seventh and eighth fastening holes, respectively, through the wooden sheathing panel, and into the wooden rafter.
When the roof safety anchor is installed on a metal roof structure, first and second screws extend through the fourth and fifth fastening holes, respectively, through a metal roof panel, and into an underlying support purlin. At least a third screw extends through one of the first and third fastening holes, through the metal roof panel, and into the support purlin. Likewise, fourth and fifth screws extend through the ninth and tenth fastening holes, respectively, through the metal roof panel, and into the support purlin. Similarly, at least a sixth screw extends through one of the sixth and eighth fastening holes, through the metal roof panel, and into the support purlin.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a roof safety anchor constructed in accordance with a preferred embodiment of the present invention.

FIG. 2 is a top view of the roof safety anchor shown in FIG. 1.

FIG. 3 is a perspective view of the roof safety anchor of FIGS. 1 and 2 installed on a metal roof structure, and showing the clip of a safety lanyard engaged therewith.

FIG. 4 is a partial cut-away perspective view of the safety anchor device shown in FIG. 3, and revealing the supporting metal purlin underlying the corrugated metal roof panel.

FIG. 5 is a cross-sectional view of the safety anchor shown in FIG. 4 taken through the section lines designated 5-5 in FIG. 4.

FIG. 6 is a perspective view of the roof safety anchor of FIGS. 1 and 2 installed on a wooden roof structure, and showing the clip of a safety lanyard engaged therewith.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIGS. 1 and 2 illustrate a roof safety anchor constructed in accordance with the teachings of the present invention, and is designated generally by reference numeral 20. Roof safety anchor 20 includes an elongated base plate 22. Base plate is substantially planar, and is preferably formed from one-quarter inch thick ASTM A36 steel plate stock. As shown best in FIG. 2, base plate 22 has a central longitudinal axis designated by dashed line 52 which extends between a first end 21 and an opposing second end 23. Base plate 22 is preferably 2.50 inches wide.
A flange 24 is connected to base plate 22 substantially midway between first end 21 and second end 23. Flange 24 is also preferably 2.50 inches wide, extends substantially perpendicular to base plate 22, and bisects base plate into a first half 25 and a second half 27. Flange 24 is also preferably made from one-quarter inch thick ASTM A36 steel plate stock. In the preferred embodiment, flange 24 is arc welded to base plate 22 using a tee butt weld configuration, forming a welded joint 26 on one side of flange 24, and forming another welded joint 28 on the other side of flange 24. Flange 24 has a hole 30 formed therein for being engaged by the hook or clip of a workman's safety lanyard, as shown for example in FIG. 3. Hole 30 preferably has a diameter of one inch (i.e., a radius of 0.5 inch). The center of hole 30 is preferably spaced one inch from the upper end 31 of flange 24, and 1.25 inches from the opposing sides of flange 24.
As noted above, one of the objectives of the present invention is to provide a roof safety anchor that may be secured to either wooden roofs or metal roofs. Still referring to FIGS. 1 and 2, a series of fastening holes 32, 34, 36, 38, and 40 are formed in first half 25 of base plate 22 for such purpose. First half 25 includes a first fastening hole 40, a second fastening hole 36, and a third fastening hole 32, each of which is substantially aligned with central longitudinal axis 52 of base plate 22. First fastening hole 40 lies closest to first end 21 of base plate 22, and third fastening hole 32 lies closest to flange 24, while second fastening hole 36 lies between first fastening hole 40 and third fastening hole 32. Preferably, fastening holes 40, 36 and 32 are spaced from each other on one-inch centers.
First half 25 of base plate 22 also includes fourth and fifth fastening holes 34 and 38, respectively. Fourth fastening hole 34 and fifth fastening hole 38 lie on opposing sides of central longitudinal axis 52. Preferably, fourth and fifth fastening holes 34 and 38 lie no closer to first end 21 of base plate 22 than does first fastening hole 40, and lie no closer to flange 24 than does third fastening hole 32. In the preferred embodiment, second fastening hole 36, fourth fastening hole 34 and fifth fastening hole 38 are all substantially aligned with each other along a first lateral axis 54 that extends substantially perpendicular to central longitudinal axis 52. It is preferred that fastening holes 34, 36 and 38 are spaced from each other on at least 0.5 inch centers.
In the preferred embodiment of the invention, second half 27 of base plate 22 is essentially a mirror image of first half 25. In this regard, second half 27 includes a sixth fastening hole 42, a seventh fastening hole 46, and an eighth fastening hole 50, each of which is substantially aligned with central longitudinal axis 52 of base plate 22. Sixth fastening hole 42 lies closest to second end 23 of base plate 22, and eighth fastening hole 50 lies closest to flange 24, while seventh fastening hole 46 lies between sixth fastening hole 42 and eighth fastening hole 50.
Second half 27 of base plate 22 also includes ninth and tenth fastening holes 48 and 44, respectively. Ninth fastening hole 48 and tenth fastening hole 44 lie on opposing sides of central longitudinal axis 52. Preferably, ninth and tenth fastening holes 48 and 44 lie no closer to second end 23 of base plate 22 than does sixth fastening hole 42, and lie no closer to flange 24 than does eighth fastening hole 50. In the preferred embodiment, seventh fastening hole 46, ninth fastening hole 48 and tenth fastening hole 44 are all substantially aligned with each other along a second lateral axis 56 that extends substantially perpendicular to central longitudinal axis 52.
In FIG. 3, roof safety anchor 20 is shown installed on a sloped metal roof. The sloped metal roof includes a series of corrugated metal roof panels, one of which is designated by reference numeral 58 in FIG. 3. Roof panel 58 may be a steel deck panel of the type commercially available under the designations “C-deck”, “R-deck”, “B-deck”, “D-deck”, or “N-deck”, for example. Such deck panel types vary in the width and spacing of the ribs and/or the depth of the valleys; the roof safety anchor may be used in conjunction with all of the aforementioned types of roof deck panels. Roof panel 58 slopes upwardly toward the ridge of the roof. In FIG. 3, the ridge of the roof is shown covered by a ridge cap 60 secured by a screw 61 (see FIG. 5) to a rib of roof deck panel 58.
As indicated in FIG. 3, roof safety anchor 20 is secured to the metal roof structure by six one-quarter inch diameter, #14×1½ inch hex head, self-drilling, self-tapping screws; within FIG. 3, five of the six screws are visible and are designated as 62, 64, 66, 68 and 70. Screw 62 is engaged with fourth fastening hole 34; screw 64 is engaged with fifth fastening hole 38; and screw 66 is engaged with third fastening hole 32. On the other side of flange 24, screw 68 is engaged with ninth fastening hole 48; screw 70 is engaged with tenth fastening hole 44; and screw 71 (see FIG. 4) is engaged with eighth fastening hole 50. All of these screws are preferably tightened to a torque of 12.5 foot pounds. The manner in which such screws pass through deck panel 58 and engage the underlying support purlin is better described below in regard to FIGS. 4 and 5. As shown in FIG. 3, a locking clip 72, engaged with safety lanyard 74, has a hooked end 76 engaged with hole 30 in flange 24. A locking member 78 prevents hook 76 from being disengaged from flange 24 unless locking member 78 is intentionally unlocked. The other end of lanyard 74 is secured to a harness worn by a workman. Such clips, lanyards, and harnesses are generally available from Miller Fall Protection of Franklin, Pa.
Turning now to FIGS. 4 and 5, a support purlin 80 extends below metal roof panel 58, and extends generally parallel to the ridge of the metal roof structure. Purlin 80 is illustrated as a C-shaped purlin, but could also be a Z-shaped purlin. Purlin 80 includes an upper surface 82, a lower surface 86, and a generally vertical mid-section 84 connecting upper surface 82 to lower surface 86. Upper surface 82 is typically two to thee inches wide. Roof panel 58 rests upon upper surface 82 of support purlin 80 proximate to the ridge of the roof. As shown best in FIG. 5, screws 62 and 64 extend through fastening holes 34 and 38, respectively, through the valley of roof panel 58, and into upper surface 82 of purlin 80. Screws 66, 68, 70 and 71 pass through their respective fastening holes in base plate 22 of roof safety anchor 20, and also pass through roof panel 58 into upper surface 82 of purlin 80.
It may be noted that roof safety anchor runs parallel to the ridge of the metal roof structure. It will also be noted that, in the event of a fall by a workman, the force exerted by the workman's safety lanyard on flange 24 of roof safety anchor 20 tends to twist roof safety anchor 20 about its central longitudinal axis 52. Were laterally-spaced fastening holes 34, 38, 44 and 48 omitted, the sudden force applied by the safety lanyard as a result of a fall would apply a torque force to the roof safety anchor and the underlying roof structure that could weaken the fasteners holding the roof safety anchor to the underlying purlin. On the other hand, by providing laterally-spaced fastening holes in base plate 20, and by installing fastening screws in such laterally-spaced fastening holes, such torque forces are more easily resisted. If desired, additional fastening screws may be inserted, for example, through fastening holes 40 and 42, for additional strength.
Referring now to FIG. 6, roof safety anchor 20 is shown installed on a wooden roof structure. Wooden sheathing panel 100 slopes upwardly toward ridge 106 of the wooden roof structure. A series of sloped wooden rafters, including those designated as 102 and 104 in FIG. 6, extend generally from the eaves of the roof up to roof ridge 106 below the wooden sheathing panels. Rafters 102 and 104 are typically 2×6 inch or 2×8 inch wooden studs; the edge of such rafters that faces upwardly, and to which the wooden sheathing panel is secured, has a rather limited width of perhaps 1.5 inches. Rafters 102 and 104 extend generally perpendicular to roof ridge 106.
Still referring to FIG. 6, roof safety anchor is secured through wooden sheathing panel 100, and to underlying rafter 102, by a series of six lag bolts. Preferably, such lag bolts are ¼ inch diameter by 3.5 inch galvanized hex-head lag bolts tightened to a torque of 6.0 foot pounds. Preferably, pilot holes are first drilled using a ⅛ inch diameter drill bit. A first lag bolt 90 extends through first fastening hole 40 through wooden sheathing panel 100, and into rafter 102. A second lag bolt 92 extends through second fastening hole 36, through wooden sheathing panel 100, and into rafter 102. A third lag bolt 94 extends through third fastening hole 32, through the wooden sheathing panel 100, and into rafter 102. Likewise, on the other side of flange 24, a fourth lag bolt 96 extends through sixth fastening hole 42, through wooden sheathing panel 100, and into rafter 102. A fifth lag bolt 98 extends through fifth fastening hole 46, through wooden sheathing panel 100, and into rafter 102. Finally, a sixth lag bolt (not visible in FIG. 6) extends through eighth fastening hole 50, through wooden sheathing panel 100, and into rafter 102.
As shown in FIG. 6, lanyard 74 and safety clip 76 generally apply a downward force on roof safety anchor in the event of a fall by a workman. This downward force is easily resisted by the series of six serially-aligned lag bolts 90,92, 94, 96, 98, etc.
Those skilled in the art will now appreciate that a simple and inexpensive roof safety anchor has been described that can be installed easily and quickly upon a roof for serving as an anchor for clips/lanyards used in personal fall-arrest systems to prevent roofing workers from falling off of roofs. The disclosed roof anchor can be secured upon a sloped roof structure either near the ridge of the roof or at a lower point. In addition, the inventive roof anchor described above can be used with either sloped wooden roofs or sloped metal roofs without modification.
While FIGS. 3-5 illustrate the roof safety anchor attached to a support purlin of a metal roof through a metal roof panel supported by such purlin, it should be understood that the described roof safety anchor could be secured directly to such support purlin if a roof deck panel is not currently installed over such purlin. Likewise, while FIG. 6 illustrates the roof safety anchor attached to a rafter of a wooden roof structure through a wooden sheathing panel, those skilled in the art will appreciate that the roof safety anchor may be directly attached to an exposed rafter.
While the present invention has been described with respect to preferred embodiments thereof, such description is for illustrative purposes only, and is not to be construed as limiting the scope of the invention. Various modifications and changes may be made to the described embodiments by those skilled in the art without departing from the true spirit and scope of the invention as defined by the appended claims.

Claims

I claim:

1. A roof safety anchor comprising in combination:

a) an elongated base plate, said base plate being substantially planar, said base plate having a central longitudinal axis extending between first and second opposing ends of said base plate;

b) a flange connected to said base plate substantially midway between the first and second ends of said base plate, said flange extending substantially perpendicular to said base plate and bisecting said base plate into a first half and a second half;

c) said flange having a hole formed therein for being engaged by a workman's safety line;

d) the first half of said base plate including first, second and third fastening holes formed therein, the first, second and third fastening holes each being substantially aligned with the central longitudinal axis of said base plate, the first fastening hole lying closer to the first end of the base plate than the second and third fastening holes, the third fastening hole lying closer to said flange than the first and second fastening holes, and the second fastening hole lying between the first and third fastening holes;

e) the first half of said base plate including fourth and fifth fastening holes formed therein, the fourth and fifth fastening holes lying on opposing sides of the central longitudinal axis of said base plate, the fourth and fifth fastening holes lying no closer to the first end of said base plate than the first fastening hole, and the fourth and fifth fastening holes lying no closer to the flange than the third fastening hole;

f) the second half of said base plate including sixth, seventh and eighth fastening holes formed therein, the sixth, seventh and eighth fastening holes each being substantially aligned with the central longitudinal axis of said base plate, the sixth fastening hole lying closer to the second end of the base plate than the seventh and eighth fastening holes, the eighth fastening hole lying closer to said flange than the sixth and seventh fastening holes, and the seventh fastening hole lying between the sixth and eighth fastening holes;

g) the second half of said base plate including ninth and tenth fastening holes formed therein, the ninth and tenth fastening holes lying on opposing sides of the central longitudinal axis of said base plate, the ninth and tenth fastening holes lying no closer to the second end of said base plate than the sixth fastening hole, and the ninth and tenth fastening holes lying no closer to the flange than the eighth fastening hole.

2. The roof safety anchor recited by claim 1 wherein:

a) the second, fourth and fifth fastening holes are substantially aligned with each other along a first lateral axis that extends substantially perpendicular to the central longitudinal axis of said base plate; and

a) the seventh, ninth and tenth fastening holes are substantially aligned with each other along a second lateral axis that extends substantially perpendicular to the central longitudinal axis of said base plate.

3. The roof safety anchor recited by claim 1 installed on a metal roof structure, the metal roof structure including corrugated metal roof panels sloping upwardly toward a ridge of the metal roof structure, and further including a support purlin extending below the metal roof panels generally parallel to the ridge of the metal roof structure, further comprising:

a) a first screw extending through the fourth fastening hole, through a selected one of said metal roof panels, and into the support purlin;

b) a second screw extending through the fifth fastening hole, through the selected metal roof panel, and into the support purlin;

c) a third screw extending through one of said first and third fastening holes, through the selected metal roof panel, and into the support purlin;

d) a fourth screw extending through the ninth fastening hole, through the selected metal roof panel, and into the support purlin;

e) a fifth screw extending through the tenth fastening hole, through the selected metal roof panel, and into the support purlin; and

f) a sixth screw extending through one of said sixth and eighth fastening holes, through the selected metal roof panel, and into the support purlin.

4. The roof safety anchor recited by claim 1 installed on a wooden roof structure, the wooden roof structure including wooden sheathing panels sloping upwardly toward a ridge of the wooden roof structure, and further including sloped wooden rafters extending below the wooden sheathing panels generally perpendicular to the ridge of the wooden roof structure, further comprising:

a) a first screw extending through the first fastening hole, through a selected one of said wooden sheathing panels, and into a selected one of the wooden rafters;

b) a second screw extending through the second fastening hole, through the selected wooden sheathing panel, and into the selected wooden rafter;

c) a third screw extending through the third fastening hole, through the selected wooden sheathing panel, and into the selected wooden rafter;

d) a fourth screw extending through the sixth fastening hole, through the selected wooden sheathing panel, and into the selected wooden rafter;

e) a fifth screw extending through the seventh fastening hole, through the selected wooden sheathing panel, and into the selected wooden rafter; and

f) a sixth screw extending through the eighth fastening hole, through the selected wooden sheathing panel, and into the selected wooden rafter.