Abstract:
A safety line anchor securable to a roof drain is disclosed. The anchor provides a secure tie down location for people working on the roof of a building. The anchor is portable so that users can carry it with them to the roof and secure it in a roof drain with minimal modification of the drain. When the worker is finished on the roof, the device can be removed and carried away. The safety line anchor comprises a body, a drain coupling assembly, and an expansion assembly. The drain coupling assembly securely fastens the anchor to the roof drain. The expansion assembly expands in the neck of the drain or the roof drain system piping to minimize wobbling of the anchor. A safety line may be attached to the body of the anchor.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to safety line anchors that provide a secure tie down location for people working on the roof of a building or other elevated surface. More specifically, this invention relates to portable versions of such anchors that can be easily transported to and from each point of use. 
     2. Background &amp; Description of the Related Art 
     Persons working on roofs or other elevated surfaces commonly utilize fall restraint and fall arrest systems to mitigate the chances of falling and injury. These fall restraint/arrest systems generally consist of an anchor, a tether or safety line, and some type of harness for attaching the tether to the worker. Examples of workers that would use these systems are contractors, roofers, custodians, and ventilation equipment technicians. 
     The present invention addresses the need for anchors for these systems to be portable and easily installed and removed on an as-needed basis. Roofs typically do not have permanent anchors installed, or if they do, the anchors are not in locations that would allow the anchors to be used in the new area of work. In such cases a new anchor must be installed, which takes additional time and expense above that already budgeted for the work. What is needed in the field of roof safety line anchors is a reusable anchor that can be carried to the jobsite, quickly installed where desired, reliably used in a fall restraint/arrest system, and easily removed when finished. Such a device is disclosed herein. 
     U.S. Pat. App. Pub. No. 2011/0048851 to Koneval, discloses a roof safety anchor that can be connected to the drain line of a roof drain system. However, Koneval relies solely on an expansion fitting to secure the anchor in the drain line which raises concerns about inadvertent release of the anchor. Also, Koneval&#39;s design requires the use of concentric spacers surrounding the stem of the device to fill the bowl of the drain to minimize wobble of the stem extending up through the bowl of the drain. This method of minimizing wobble is limited by the size of the spacers preinstalled on the device. In addition, because the spacers are of fixed diameters, the device must carry several different sizes due to the uncertainty of the roof drain size which will be encountered. By carrying a variety of spacers on the device unnecessary bulk and weight are added to the device. Furthermore, Koneval&#39;s device is intended to frictionally engage the interior walls of the “drain line” below the drain and not the drain neck or the portion of the drain piping within the neck area. This could be problematic if the anchor is intended to be used in a roof drain that has only a short segment of vertical drain pipe connecting to the drain. In such situations there may not be a sufficient length of drain piping below the drain to safely use Koneval&#39;s device. In view of the foregoing, there remains a need for a portable safety line anchor particularly well adapted for use on a roof including such an anchor which can be secured within or through a drain in a roof. 
     SUMMARY OF THE INVENTION 
     The present invention comprises a safety line anchor removably securable within a roof drain. The roof drain includes a neck connectable to a drain pipe, a bowl projecting outward from the neck, and a clamping flange projecting outward from the upper end of the bowl. The roof drain includes a plurality of bolt receivers formed in the bowl. A clamping ring connects to the bowl over the clamping flange by bolts extending into the bolt receivers in the bowl, and depending on roof construction the roof membrane is generally clamped between the clamping ring and the clamping flange. 
     The safety line anchor comprises a body having an upper end and a lower end. An expansion assembly is mounted on the lower end of the body, and prior to expansion the expansion assembly is sized to fit within the neck of the roof drain or within the drain pipe to which the neck is connected. The expansion assembly is expandable radially outward and sized to frictionally engage the inner surface of the neck or the drain pipe within the neck upon expansion. 
     The safety anchor further comprises a drain coupling assembly which includes a hub vertically adjustable relative to the expansion assembly. The drain coupling assembly includes a plurality of forks with each fork being adjustable outward relative to the hub. When the anchor is installed each fork will at least partially surround one of the bolts or bolt receivers of the roof drain. The anchor also includes a means for attaching a safety line to the anchor. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a safety line anchor securable to a roof drain shown installed in a roof drain. 
         FIG. 2  is an exploded perspective view of the safety line anchor relative to a roof drain in which it is installed as shown in  FIG. 1 . 
         FIG. 3  is an exploded perspective view of the safety line anchor in  FIG. 1 . 
         FIG. 4  is a fragmentary, cross-sectional view of the safety line anchor installed in a drain taken along line  4  of  FIG. 1 . 
         FIG. 5  is an enlarged and fragmentary perspective view of a bolt engaging member of the safety line anchor with portions removed to show interior detail. 
         FIG. 6  is an enlarged and fragmentary cross-sectional view taken along line  6  of  FIG. 5 . 
         FIG. 7  is a cross-sectional, fragmentary view similar to  FIG. 4  showing a neck of the drain extending in abutting relationship instead of overlapping relationship with a drain pipe. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure. The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof. 
     Certain terminology will be used in the following description for convenience in reference only and will not be limiting. For example, the words “upwardly,” “downwardly,” “rightwardly,” and “leftwardly” will refer to directions in the drawings to which reference is made. The words “inwardly” and “outwardly” will refer to directions toward and away from, respectively, the geometric center of the embodiment being described and designated parts thereof. Said terminology will include the words specifically mentioned, derivatives thereof and words of a similar import. 
     Referring to the drawings in more detail, reference numeral  1  refers to a roof drain of a conventional design to which a safety line anchor  2  of the present invention may be attached. Roof drain  1  includes a bowl  4  that gathers and funnels water entering roof drain  1  toward a circular bowl opening  6  located in the center of the floor of bowl  4 . Bowl opening  6  opens into an integrally formed cylindrical neck  7  which projects downward from the floor of bowl  4 . Neck  7  is sized according to drainage requirements of the roof being served. Neck  7  is in flow communication with and mates with or abuts roof drain system piping  9 . Referring to  FIG. 5 , the drain pipe  9  is shown inserted in neck  7 . However it is to be understood that the safety line anchor  2  could be used with drains  1  in which the neck  7  is sized to be and is inserted into the open end of the drain pipe  9  or in which a lower end of the neck  7  abuts the upper end of the drain pipe  9  and an elastomeric sleeve  10  spans the joint between the neck  7  and drain pipe  9  as shown in  FIG. 7 . 
     Roof drain  1  further comprises an annular clamping flange  11  formed at the rim  12  of bowl  4 . Clamping flange  11  includes a planar top surface  13  and an overhang  14  projecting outward from rim  12  and encircling the top of bowl  4 . Integrally attached to the underside of overhang  14  are several downward facing vertical threaded bolt receivers  18 , or bosses, for receiving bolts that secure roof drain  1  to a roof. In a typical embodiment four bolt receivers  18  are formed in and equally spaced around the outside of bowl  4 . 
     Roof drain  1  further includes a clamping ring  20  positioned above the top of clamping flange  11  for clamping flashing  21  therebetween. Clamping ring  20  comprises an annular band  22  having a band width and diameter similar to that of clamping flange  11 . At the outer edge of annular band  22 , a plurality of teeth  23  project perpendicularly upward from the band. Each tooth  23  is generally trapezoidal in shape and located longitudinally adjacent to another tooth  23  such that the gap between the teeth forms an inward sloping valley. This circular row of teeth lines the outer edge of annular band  22 . Clamping ring  20  also comprises four equally spaced bolt support flanges  24  projecting inward from the annular band  22  with a bolt receiving slot  25  formed in and extending into each bolt support flange  24  from an inner end thereof. 
     Roof drain  1  further comprises four upward facing vertical threaded clamping bolt receivers  29 , or bosses, integrally formed on the interior wall of bowl  4 . The clamping bolt receivers  29  are equally spaced about the interior circumference of the wall of bowl  4 . The structure of each clamping bolt receiver  29  protrudes slightly into the interior space of bowl  4 , and a threaded bore extending vertically through each clamping bolt receiver  29  is intended to align with one of the bolt receiving slots  25  when clamping ring  20  is placed atop clamping flange  11 . Referring to  FIG. 4 , clamping ring  20  is fastened atop clamping flange  11  by positioning threaded stem  31  of clamping bolt  33  through receiving slots  25 , and then threadingly securing the clamping bolts  33  in clamping bolt receivers  29 . A strainer or grate, not shown, is typically secured over the rest of the drain assembly  1  shown. However, the strainer is removed prior to installation of the safety line anchor  2  therein. It is foreseen that other roof drain configurations may be used with the present invention, however the configuration described herein is thought to be the most common. 
     As best seen in  FIGS. 2 and 3 , the safety line anchor  2  comprises an externally threaded anchor body or vertical stem  39 , an expansion assembly  41 , a drain coupling assembly  43 , and a safety line connector assembly  45 . The expansion assembly  41  is mounted on a lower end of the anchor body  39  and is sized for insertion into the upper end of the drain pipe  9  where it preferably aligns with drain neck  7  or within the neck  7  abutted against the upper end of pipe  9 . Once inserted therein, the expansion assembly  41  may be expanded as described hereafter to restrain the vertical stem or body  39  from wobbling. The drain coupling assembly  43  is adapted to engage a portion of the drain  1  to prevent withdrawal of the anchor  2  from drain  1 . The drain coupling assembly  43  is threadably mounted on the anchor body  39  to permit vertical adjustment of the drain coupling assembly  43  relative to the expansion assembly  41  to position the drain coupling assembly  43  in position to engage a portion of the drain  1 . Safety line connector assembly  45 , to which a safety line may be securely connected, is pivotally mounted on the anchor body  39 . 
     In the embodiment shown, the body  39  comprises an externally threaded shaft or rod  50  with a bore  51  extending axially therethrough from end to end. The body  39  generally forms a base of the anchor  2  on which the other components are mounted. In one embodiment the shaft  50  is approximately twelve inches long or tall with an upper end  52  and lower end  53 . It is foreseen that the shaft  50  could be longer or shorter. 
     The expansion assembly  41  which is connected to the lower end  53  of the shaft  50  generally comprise a top plate  56  adjacent the lower end  53  of shaft  50 , a bottom plate  58 , compression plug  60  positioned between the top and bottom plates  56  and  58 , and a threaded rod  62  connected to the bottom plate  58  and extending through the anchor body  39  and connected to a wing nut or handle  65  positioned at the upper end  52  of shaft  50  for drawing the threaded rod  62  and attached bottom plate  58  upward to compress the compression plug  60  therebetween. The top plate  56  is annular with a hole  67  extending therethrough aligned with the axial bore  51  in shaft  50  and through which rod  62  extends. The top plate  56  generally rests on top of compression plug  60  which urges the top plate  56  into abutting relationship with the lower end  53  of the shaft  50 . The top plate  56  is generally sized to be marginally larger than the largest drain pipe in which the safety line anchor  2  is intended to be installed. The hole  67  in top plate  56  is sufficiently large to allow top plate  56  to move freely along rod  62  but smaller than the diameter of anchor body  39  so that it cannot be slid past the anchor body  39 . 
     Bottom plate  58  is an annular disc sized to be marginally smaller in diameter than the smallest drain pipe in which safety line anchor  2  is intended to be installed. Bottom plate  58  is immovably held in place with respect to rod  62  via a key nut  69  and a radial mounting flange  73 , both of which have been fixedly attached, such as by welding, to the lower end  75  of rod  62 . Mounting flange  73  is a circular disc approximately one-third the diameter of bottom plate  58 . Fixedly attached to the top of mounting flange  73  is key nut  69  which is threadably engaged and fixedly attached to rod  62 . A keyhole  77  shaped and sized to match the exterior perimeter shape of key nut  69  is created in bottom plate  58  proximate the plate&#39;s center. Bottom plate  58  is placed on key nut  69  by installing key nut  69  through keyhole  77  and then fixedly attaching bottom plate  58  to key nut  69 . Key nut  69  is then fixedly attached to mounting flange  73 , and the bottom plate  58 , key nut  69 , and mounting flange  73  assembly is fixedly attached to the lower end  75 . Bottom plate  58 , mounting flange  73  and key nut  69  are all immovable with respect to rod  62 . 
     Resting on top of bottom plate  58  and below top plate  56  is compression plug  60 . Compression plug  60  is a hollow cylindrical plug made of flexible and resilient material that returns to its fabricated or resting cylindrical shape after being deformed due to external forces. Compression plug  60  has ridges or other texture on the exterior surface of its cylindrical walls that aid in gripping the interior walls of the roof drain pipe  9  or roof drain neck  7 . Threaded rod  62 , which is longer than anchor body shaft  50 , extends through the hollow cylindrical space inside compression plug  60 , through the hole  67  in top plate  56 , through axial bore  51  in anchor body shaft  50  and through wing nut or handle  65  positioned above the upper end  52  of anchor body shaft  50 . Fixedly attached to the upper end  52  of shaft  50  is a circular support plate  80  against which the handle or wing nut  65  bears. 
     Handle  65  generally comprises two outwardly projecting grips  83  attached to an internally threaded cylindrical nut or sleeve  86 . Each grip  83  is attached to the outer wall of nut  86  and arranged such that it extends away from nut  86  at an angle slightly above horizontal. Handle  65  is threaded onto an upper end  89  of rod  62  and into engagement with the support plate  80 . Further axial rotation of handle  65  about rod  62  and against support plate  80  draws the rod  62  up through nut  86  drawing bottom plate  58  upward toward top plate  56  compressing the compression plug  60  therebetween causing it to expand outward to engage an inner surface of a pipe  9  or neck  7  in which it is installed. 
     The drain coupling assembly  43  includes an internally threaded collar  90  threadably engaged with shaft  50  above top plate  56  of expansion assembly  41 . Collar  90  is vertically adjustable to accommodate differences in the depths of drains  1  with which it might be used and the location of the clamping bolts  33  and clamping bolt receivers  29  in such drains  1 . Attached to the exterior of collar  90  are four equally spaced threaded studs  93  projecting radially outward therefrom. Slidably mounted on each stud  93  is a bolt engaging member or forked collar  97  which slides axially along the stud  93 . Forked collar  97  has a generally cylindrical shape with a first end  98  that is flat and faces collar  90 , and a second opposing end  100  that is forked resulting in two prongs  101  and a valley  102  therebetween formed by groove  103 . The forked collars  97  are adapted to engage or surround either clamping bolts  33  or clamping bolt receivers  29  depending upon the specific configuration of roof drain  1 . When safety line anchor  2  is installed, prongs  101  wrap around the vertical sides of bolt  33  or bolt receiver  29 , and the bolt or receiver rests in or as near as possible to the fork valley  102 . Forked collar  97  is pushed against bolt  33  or bolt receiver  29  and held in place by a jam nut  99  threadably engaged with stud  93  and abutting the first end  98  of the forked collar. When forked collar  97  is in place against bolt  33  or receiver  29  and jam nut  95  is threadably secure against forked collar  97  lateral movement of stud  93  is eliminated. Because lateral movement of stud  93  is eliminated, rotational movement of collar  90  is also eliminated. When forked collar  97  is engaged with bolt  33  or bolt receiver  29  the collar  90  is also trapped under clamping ring  20  thus also minimizing vertical movement of forked collar  97 , stud  93 , and collar  90  and preventing pulling of the safety line anchor  2  from the drain  1 . 
     Implanted in stud  93  is a ball detent or position retaining device  104  comprising a pocket  105 , spring  107 , ball  110 , and lip  112 . Position retaining device  104  keeps forked collar  97  from accidentally sliding off of stud  93  and potentially falling into roof drain  1  and the associated roof drain system piping  9 . Within pocket  105  is a spring  107  in a state of compression and a ball  110  located next to the first end of spring  107 . The second end of spring  107  presses against the interior surface of the floor of pocket  105 . Ball  110  is pressed by spring  107  against the circumferential lip  112  of pocket  105 . A portion of ball  110  is allowed to protrude slightly above lip  112 , however the majority of ball  110  is retained by lip  112  within pocket  105 . A small threaded bore  114  is created perpendicular to and through the axis of stud  93  proximate its unattached end, and pocket  105  is threadingly inserted into bore  114  such that lip  112  is generally level with the threaded surface of stud  93 . When pocket  105  is in place within bore  114 , a portion of ball  110  projects slightly above the threaded surface of stud  93 . A circumferential channel  116  is formed in the interior wall of forked collar  97  proximate first end  98 . Channel  116  is sized to receive the portion of ball  110  projecting above the threaded surface of stud  93 . As forked collar  97  slides axially along stud  93 , the interior surface of forked collar  97  presses ball  110  down such that the outside of ball  110  is generally even with the threaded surface of stud  93 . When forked collar  97  moves axially outward along stud  93  far enough that channel  116  is over ball  110 , ball  110  projects upward into channel  116  due to the compression force of spring  107 . When ball  110  is in channel  116  the ball catches the wall of channel  116  and discourages further outward movement of forked collar  97 . 
     The safety line connector assembly  45  comprises a cylindrical sleeve or pivot sleeve  119  surrounding shaft  50 , and the length of the pivot sleeve  119  shown is approximately half the length of shaft  50 . Pivot sleeve  119  rotates freely around shaft  50  and its vertical position along shaft  50  is adjustable. A lower end of the pivot sleeve  119  is supported on the drain coupling assembly  43 , and an upper stop or stop nut  122  threaded onto shaft  50  may be threaded against an upper end of the pivot sleeve  119  to fix its vertical position relative to the shaft  50 . Stop  122  serves to limit the distance that sleeve  119  can travel vertically upward along shaft  50 . Pivot sleeve  119  is confined to a zone of travel along shaft  50  that is bounded by upper stop  122  and collar  90 . This zone of travel is adjustable by the user by adjusting the position of upper stop  122  and collar  90  relative to shaft  50 . It is likely that the user will want to minimize the zone of travel when the safety line anchor  2  is in use so that there is minimal movement of sleeve  73 . Connected to pivot sleeve  119  via mounting knuckle  125  is a d-ring  128 , which is used for connecting a safety line  130  to the safety line anchor  2 . Mounting knuckle  125  is in the form of a barrel hinge that surrounds the straight leg of d-ring  128  such that the ring can rotate freely about the axis of the straight leg. D-ring  128  also serves as a handle for transporting the safety line anchor  2 . 
     Prior to installation of the safety line anchor  2 , the jam nuts  99  are threaded back towards the collar  90  and the bolt engaging members  97  are pulled toward the collar  90  so that the drain coupling assembly  43  may be inserted in the drain  1  past the clamping ring  20 . The handle  65  is loosened so that the bottom plate  58  is advanced far enough away from the top plate  56  so that the top and bottom plates  56  and  58  do not compress the compression plug  60 . The stop nut  122  is threaded upward on shaft  50  so that the safety line connector assembly  45  and the drain coupling assembly  43  can be moved upward on shaft  50  to adjust the position of the drain coupling assembly  43  to align with the portion of the drain  1  to which it is to be connected. 
     To install the safety line anchor  2 , the expansion assembly  41  is inserted into drain pipe  9 , or drain neck  7  depending on drain configuration, with the top plate  56  resting on the bottom of the bowl  4  around the opening  6 . The handle  65  of the expansion assembly  41  may then be rotated to draw the rod  62  upward, pulling the bottom plate  58  upward toward top plate  56  compressing the compression plug  60  therebetween and causing it to expand outward to engage the pipe  9  or drain neck  7  depending on the drain installation. Engagement of the pipe  9  or neck  7  by compression plug  60  steadies the anchor  2  from wobbling. 
     The vertical position of the drain coupling assembly  43  is then adjusted to align the bolt engaging members  97  with the clamping bolts  33  (or bolt receivers  29  if applicable) of the drain  1 . Vertical adjustment of the drain coupling assembly  43  is accomplished by rotating threaded collar  90  relative to threaded anchor body  30 . The bolt engaging members are each slid outward on the associated stud  93  until the prongs  101  surround the respective bolt  33  or bolt receiver  29  below the bolt support flange  24  and then the jam nuts  99  are threaded outward on studs  93  to prevent retraction of the bolt engaging members  97 . Stop nut  122  is then threaded down onto pivot sleeve  119  of the safety line connector assembly  45  to fix its vertical position and a safety line  130  may then be connected to the D-ring  128  and the safety line anchor system is ready for use. 
     Many different arrangements of the various components depicted, as well as components not shown, are possible without departing from the scope of the claims below. Embodiments of the technology have been described with the intent to be illustrative rather than restrictive. Alternative embodiments will become apparent to readers of this disclosure after and because of reading it. Alternative means of implementing the aforementioned can be completed without departing from the scope of the claims below. Certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations and are contemplated within the scope of the claims.