Patent Publication Number: US-2022235567-A1

Title: System, method and apparatus for fall protection of workers at a construction site

Description:
CROSS-REFERENCE TO RELATED APPLICATION AND CLAIM OF PRIORITY 
     This application is a continuation-in-part of U.S. patent application Ser. No. 16/424,223, filed on May 28, 2019, which claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application No. 62/677,836 filed on May 30, 2018. The above-identified provisional patent application is hereby incorporated by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The present invention relates in general to construction safety and, in particular, to a mount plate of a fall protection system for workers at construction job sites. 
     BACKGROUND 
     Construction industry stakeholders, including, without limitation, residential and commercial builders, framers and insurers, are concerned about protecting workers from falls from unfinished structures (for example, structures under construction or being repaired). Despite helpful regulation and improvements in safety equipment, numerous opportunities for reducing the incidence of fall-related injuries and deaths associated with building construction remain. Fatalities from falls typically are a leading cause of workplace deaths in construction. Accordingly, improvements in fall protection of workers at construction sites continue to be a source of technical challenges and improvement in the art. 
     SUMMARY 
     Embodiments of a system, method and apparatus for the fall protection of workers at construction sites are disclosed. For example, the fall protection system provides improved protection for workers from falls at a worksite for an unfinished structure, such as a dwelling or building formed with a wood or metal frame. Embodiments of the systems according to this disclosure include one or more towers configured to be coupled together with a horizontal lifeline. In certain embodiments, each tower has a base configured to be removably coupled to a bottom of the wood or metal frame. A lower slip sleeve is, in various embodiments, configured to be slidably coupled to the base. The lower slip sleeve has an elongate opening extending substantially therethrough. According to some embodiments, an internal piece is configured to be slidably received in the elongate opening and coupled to the lower slip sleeve. In some embodiments, an upper slip sleeve is coupled to an exterior of the internal piece such that the upper slip sleeve is not movable relative to the internal piece. The upper slip sleeve has, in certain embodiments, an upper elongate opening extending to the internal piece. Further, a mount plate is, in various embodiments, configured to be slidably coupled to an exterior of the upper slip sleeve and mounted to a top of the wood or metal frame. Finally, a stanchion is, in certain non-limiting examples described herein, configured to be slidably received in the upper elongate opening and coupled to the upper slip sleeve. The stanchion is, in various embodiments, configured to support at least one end of the horizontal lifeline. 
     In other embodiments, a method of providing fall protection on levels of a building that is under construction is disclosed. The method can include constructing an initial level of the building with a wood or metal frame and installing a fall protection system to the initial level of the frame. The method can include further constructing and framing the frame to a second level of the frame above the initial level of the frame while providing fall protection for construction workers with the fall protection system. Thereafter, the method can include uninstalling the fall protection system from the initial level of the frame. Further, the method can include installing the fall protection system to the second level of the frame, such that the fall protection system is not mounted to any portion of the initial level of the frame. The method can further include constructing and framing the frame to a third level, or higher level, of the frame above the second level of the frame while providing fall protection for construction workers with the fall protection system. 
     The foregoing and other objects and advantages of these embodiments will be apparent to those of ordinary skill in the art in view of the following detailed description, taken in conjunction with the appended claims and the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       So that the manner in which the features and advantages of the embodiments are attained and can be understood in more detail, a more particular description may be had by reference to the embodiments thereof that are illustrated in the appended drawings. However, the drawings illustrate only some embodiments and therefore are not to be considered limiting in scope as there may be other equally effective embodiments. 
         FIG. 1A  illustrates a fall protection system according to certain embodiments of this disclosure as deployed on the first floor of a building frame under construction. 
         FIG. 1B  illustrates a fall protection system according to various embodiments of this disclosure, as deployed on a second or higher floor of a building frame under construction. 
         FIG. 2  illustrates a fall protection system according to some embodiments of this disclosure, as configured at first, second and third installation heights, respectively. 
         FIG. 3  illustrates a top view of a base plate for a fall protection system according to various embodiments of this disclosure. 
         FIG. 4  illustrates a top view of a mount plate for a fall protection system according to certain embodiments of this disclosure. 
         FIG. 5A  illustrates aspects of a method of implementing a fall protection system on an exterior of a structure under construction according to various embodiments of this disclosure. 
         FIGS. 5B-5D  illustrate components of a fall protection system according to some embodiments of this disclosure. 
         FIG. 6  illustrates, in isometric view, a fall protection system according to certain embodiments of this disclosure. 
         FIG. 7  illustrates, in isometric view, a fall protection system according to various embodiments of this disclosure; 
         FIG. 8  illustrates a fall protection system according to various embodiments of this disclosure; 
         FIGS. 9A-9C  illustrate three views of a multi-piece mount plate according to some embodiments of this disclosure; and 
         FIGS. 10A-10C  illustrate three views of a pivotable multi-piece mount plate according to various embodiments of this disclosure. 
     
    
    
     The use of the same reference symbols in different drawings indicates similar or identical items. 
     DETAILED DESCRIPTION 
     Before any embodiments according to this disclosure are explained in detail, it is to be understood that embodiments according to the present disclosure are not limited by the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. 
       FIGS. 1-10C  illustrate some embodiments of a system, method and apparatus for a fall protection system  101  according to the present disclosure. The fall protection system  101  provides support for a lifeline  105  to which can be tethered, such that the tether and lifeline can prevent a human worker from contacting the ground or a hard surface below as a result of a fall from an unfinished structure  21  comprising a wood or metal frame  23 . According to various embodiments, wood or metal frame  23  comprises structural members (for example, wood or metal studs) of unfinished structure  21 . In some embodiments, system  101  includes one or more towers  103  (for example, multiple instances of tower  103 , as shown in the explanatory examples of  FIGS. 1A and 1B ). Towers  103  can be configured to be coupled together with one or more lifelines  105 , such as the lifeline  105  shown in  FIG. 1A . According to various embodiments, lifeline  105  comprises a section of material with high tensile strength and suitable abrasion resistance (for example, steel cable or climbing rope) with one or more eye ends, crimped loops or other terminal fittings for attachment to tower  103 . 
     According to certain embodiments, tower  103  comprises a plurality of tubing components forming stanchions and sleeves as discussed herein. Referring to the non-limiting examples of  FIGS. 1-10C , square-shaped cross-sectional bodies are shown, but embodiments according to the present disclosure are not limited thereto and tower  103  can be constructed from components with circular, obround and other cross-sectional shapes. According to various embodiments, tower  103  includes a bottom plate or base  111  that is configured to be removably coupled, such as with fasteners, to a portion (e.g., a bottom  25 ) of the wood or metal frame  23 . In addition, or alternatively, the base  111  can be mounted to the foundation of the unfinished structure  21  with fasteners. The base  111  is, in certain embodiments, secured to the foundation with cast-in-place anchor bolts, at 4-foot centers. In applications, where the floor of the installation site permits the use of fasteners (for example, floors constructed using wood and/or metal decking), base  111  is, in some embodiments, secured to the decking and joists with one or more fasteners. 
     According to certain embodiments, base  111  comprises a vertical sleeve  112  ( FIGS. 3 and 6 ) in which a lower slip sleeve  121  is configured to be mounted. In some embodiments, the lower slip sleeve  121  is configured to be slidably coupled to the base  111 . As illustrated in the non-limiting example of  FIG. 6 , the lower slip sleeve  121  is coupled to the base  111  (and other components can be reversibly mechanically coupled) with one or more fasteners, (for example, fasteners which can be readily installed and removed in the field, such as removable detent pins or clamps). Removable detent pins are, in various embodiments, configured to selectively reversibly couple or mount two or more components of system  101  together. The lower slip sleeve  121  can have a hollow internal cavity, such as an elongate opening  123  ( FIG. 2 ), extending substantially therethrough. 
     According to some embodiments, tower  103  further includes an internal piece  131 , such as a rod or section of square tubing, which can be configured to be slidably received in the elongate opening  123 . The internal piece  131  can, in various embodiments be coupled to the lower slip sleeve  121 , such as with a removable detent pin. 
     In various embodiments, tower  103  also includes an upper slip sleeve  141  coupled to an exterior of the internal piece  131 . Upper slip sleeve  141  can be permanently mounted to (for example, by welding or riveting) and not movable relative to the internal piece  131 . The upper slip sleeve  141  can include an upper elongate opening  143  (as shown, for example in  FIG. 2 ) that extends to the internal piece  131  located inside the upper slip sleeve  141 . 
     In addition, the tower  103  is, in various embodiments, coupled to a mount plate  151 . The tower  103  can be configured to be slidably coupled or extend through an aperture (e.g., hole  152  in  FIG. 4 ) in the mount plate  151 . In particular, the hole  152  can receive an exterior of the upper slip sleeve  141 . The mount plate  151  can be mounted, such as with fasteners, to a portion (e.g., a top  27 ) of the wood or metal frame  23 . The mount plate  151  can be attached to a top plate, and the upper slip sleeve  141  can be secured to the mount plate  151  with fasteners. In some embodiments, upper slip sleeve  141  is secured to mount plate  151  with fasteners suitable for field use, rather than nails. Although the mount plate  151  is shown in the illustrative examples of  FIGS. 1A, 1B and 4  as mounted to the top horizontal surface of the wood or metal frame  23 , embodiments according to this disclosure are not limited thereto, and mount plate  151  can also be mounted to vertical side surfaces of the wood or metal frame  23 .  FIGS. 5A-D ,  7  and  8  illustrate examples of mount plates  151  mounted to the side(s) of structures. According to various embodiments, mount plates  151  which can be side-mounted versions can facilitate installation of joists, joist trusses, rafters or roof truss structures on top of the wood or metal frame  23 . 
     Embodiments of the fall protection system  101  can include one or more stanchions  161 . As shown in the non-limiting example of  FIG. 2 , each stanchion  161  can be configured to be slidably received in the upper elongate opening  143  and coupled to the upper slip sleeve  141 , such as with a removable detent pin. The stanchion  161  can be configured to support an end of at least one of the lifelines  105 . According to various embodiments, the upper end of each stanchion  161  includes hardware (for example, carabiners, clips or other hardware) to couple with and secure a plurality of additional lifelines  105 . Further examples of hardware for coupling lifelines  105  to stanchion  161  include, without limitation, one or more brackets or eyebolts. 
     According to various embodiments of fall protection system  101 , internal piece  131 , upper slip sleeve  141 , mount plate  151 , and stanchion  161  are configured one or more of the above-referenced components can be moved to adjust the height of the apparatus and lifeline  105 . According to various embodiments, the internal piece  131 , the upper slip sleeve  141 , the mount plate  151 , and the stanchion  161  can be adjusted with respect to lower slip sleeve  121  to define a desired vertical elevation of each of the towers  103 . According to certain embodiments, for example, embodiments shown in the illustrative example of  FIG. 2 , each tower  103  has a plurality (for example, at least three) settings for vertical elevation, defined, in some instances, by the position of through holes in one or more of slip sleeve  121 , internal piece  131 , or upper slip sleeve  141 . For example, a first vertical elevation from the base  111  to the mount plate  151  of each tower  103  is 8 feet. Like many dimensions in the construction industry, the distance “8 feet” is a nominal measurement and can be interpreted to encompass about 8 feet or substantially 8 feet. In another example, a second vertical elevation from the base  111  to the mount plate  151  of each tower  103  is about 9 feet. Embodiments also can include a third vertical elevation from the base  111  to the mount plate  151  of each tower  103  that is substantially 10 feet. Accordingly, these styles of vertical stanchion systems can include a receiver-type arrangement at the top that permits the upper vertical stanchion to be positioned about two feet into the section below it. The upper vertical stanchion  161  can have nominal heights above the corner or intermediate brackets of the wood or metal frame  23  of (for example) about 6 feet or about 7 feet, depending upon user preference and job site conditions. According to various embodiments, upper vertical stanchion  161  can have nominal heights above the corner or intermediate brackets of wood or metal frame  23  of greater than 7 feet. 
     According to certain embodiments, fall protection system  101  can be implemented without tensioning cables or rigid support between vertical elements of the system and the ground to help resist cantilevering of the vertical components from loads on lifeline  105 . Accordingly, by ensuring sufficient structural strength without the use of tensioning cables, guy wires, or rigid supports certain embodiments according to this disclosure can be implemented in a wider variety of contexts (for example, in tighter spaces or where the surrounding ground cannot hold tensioning cables). Moreover, in various embodiments, fall protection system  101  is not fastened to any portion of a concrete foundation of the unfinished structure  21 . Surprisingly, in certain embodiments, the structural integrity needed to support lifeline  105  on stanchions  161  can be achieved by coupling fall protection system  101  to the wood or metal frame  23  of the unfinished structure  21  to secure it to the unfinished structure  21 . Further, and as described herein, towers  103  of fall protection system  101  can be attached to one or more of an interior of the unfinished structure  21 , and concave corners of the wood or metal frame  23 , interior, concave corners of the wood or metal frame. Accordingly, embodiments of fall protection system  101  can provide flexible, robust solutions for supporting lifelines across a wide variety of site geometries, thereby providing workers with improved fall protection. 
       FIGS. 5A-5D  illustrate aspects of a fall protection system  101  according to certain embodiments of this disclosure. Referring to the non-limiting example of  FIG. 5A , a wood or metal frame  23  can define an exterior of the unfinished structure  21 , as shown. Depending on characteristics of the job site (for example, the degree of completion of the structure, and the availability of access to suitable anchor surfaces) towers  103  may be required to be positioned located only in or on a respective corner of the unfinished structure  21 . However, in certain embodiments, suitable anchor surfaces fall protection system  101  are provided on the interior of the structure, or on a combination of interior and exterior surfaces. According to certain embodiments wood or metal frame  23  has outer or external corners  29  (as shown in  FIGS. 5A and 5B ) that are convex. In some embodiments (for example, embodiments as shown in  FIGS. 5A, 5B, 7 and 8 ), the tower  103  can be located on the outer or external corner  29  of the wood or metal frame  23  of the unfinished structure  21 . Referring to the non-limiting example of  FIG. 5A , an instance of a tower  103   a  removably attached to an outside corner of the structure is shown, as is an instance of a tower  103   b  removably attached to a planar portion of the structure, and an instance of a tower  103   c  removably attached to an inside corner of the structure. According to certain embodiments, base  111  and the mount plate  151  can have concave portions  117 ,  157 , respectively, that are configured to be complementary to and mate with, external corners  29  which are convex. 
     Referring to the non-limiting examples of  FIGS. 5A, 5C, 7 and 8 , a wood or metal frame  23  defines at least a portion of the exterior of the unfinished structure  21 , and the wood or metal frame  23  can include external planar surfaces  31 . According to certain embodiments, base  111  and mount plate  151  include planar portions  119 ,  159 , respectively, which are configured to be complementary to and mate with, external planar surfaces  31 . In various embodiments, planar portions  119 ,  159  abut with, and are fastened to the external planar surfaces  31 . Put differently, in some embodiments, at least one of the towers  103  can laterally abut at least a portion of the planar, vertical wall of the wood or metal frame  23  of the unfinished structure  21 , and not be on or in a corner thereof. 
     According to certain embodiments, (for example, certain embodiments as shown in  FIGS. 5A and 5D ), tower  103  can be located on an inner or concave corner of the wood or metal frame  23  of the unfinished structure  21 . In various embodiments, the strength and support of the tower  103  required to provide fall protection is provided, at least in part by the wood or metal frame  23 . According to some embodiments, by leveraging the structural strength of the building site itself, fall protection system  101  can be utilized across a broader range of construction sites than systems which rely on points away from the structure under construction for support. 
     In some embodiments of the fall protection system  101 , the base  111  has a generally triangular shape comprising a horizontal base plate  113  ( FIGS. 1, 3 and 6 ). According to various embodiments, base  111  also includes vertical base plate portions  115  that extend (e.g., upward or downward) from the horizontal base plate  113 . As shown in the non-limiting example of  FIG. 1 , the vertical base plate portions  115  are, in certain embodiments, configured to be fastened to the bottom  25  of the wood or metal frame  23 . 
     Similarly, various embodiments of the mount plate  151  include a horizontal mount plate  153  (as shown, for example, in  FIG. 6 ). In some embodiments, mount plate  151  includes vertical mount plate portions  155  that extend (e.g., downward) from the horizontal mount plate  153 . The vertical mount plate portions  155  are, in some embodiments, configured to be fastened to the top  27  of the wood or metal frame  23 . In additional or alternative embodiments, the base  111  and the mount plate  151  have any other appropriate shapes (i.e., rectangular, pyramidal, etc.) and wall configurations. 
     As depicted in the non-limiting examples shown in  FIGS. 1A, 1B and 2 , the fall protection system  101  can include one or more auxiliary support members  181 . Auxiliary support member  181  is, in some embodiments, oriented at a diagonal relative to vertical and provides additional strength, in particular, resistance against cantilevering of stanchions  161 , to the fall protection system  101 . In certain embodiments, auxiliary support member  181  has a lower end  183  that is configured to be coupled to the bottom  25  of the wood or metal frame  23 . Alternatively, the lower end  183  is configured to be mounted to the foundation of the unfinished structure  21 . In various embodiments, lower end  183  comprises a sleeve for the bottom of auxiliary support member  181 , analogous to sleeve  112  ( FIG. 2 ) for the bottom of the lower slip sleeve  121 . In certain embodiments, auxiliary support member  181  includes an upper end  185 , which can be removably coupled or mounted (for example, on a pivot) to the upper slip sleeve  141  or to the mount plate  151 . Referring to the non-limiting example of  FIG. 2 , a removable detent pin or clip may be used to secure auxiliary support member  181  to tower  103 . 
     Some embodiments of auxiliary support member  181  comprise a slip sleeve, for example, a slip sleeve formed from square tubing. For example, in some embodiments, the slip sleeve includes a hollow rod  187 , and an inner rod  189  which is configured to be slidably mounted in an interior of the hollow rod  187 . In various embodiments inner rod  189  can be coupled to (for example, with a removable detent pin) hollow rod  187  to set a length of the auxiliary support member  181  to a selected length. The auxiliary support member  181  can be adjustable to support the tower  103  at its various vertical elevations, as described herein. 
     In the non-limiting example of  FIG. 1A , a fall protection system  101  according to various embodiments of this disclosure, is shown installed on the ground floor or level (e.g., lowermost floor) of an unfinished structure  21 . In the non-limiting example of  FIG. 1B , a fall protection system  101  according to some embodiments, is shown installed on a floor (e.g., the second floor, the third floor, etc.) that is vertically above the ground floor of the unfinished structure  21 . As illustrated in  FIGS. 1A and 1B  embodiments of the fall protection system  101  are attached to the wood or metal frame  23 , rather than the foundation and/or any portion of the floor below which the fall protection system  101  is installed. By not requiring that fall protection system  101  be anchored to the foundation, the range of possible configurations and scenarios where fall protection system  101  is enhanced. As one non-limiting example, in certain embodiments, fall protection system  101  could be reinstalled upwards as additional floors are added to unfinished structure  21 . According to various embodiments, such as, for example, embodiments as illustrated in  FIG. 1B , the fall protection system  101  can be mounted to portions of the upper frame, such as ceiling/floor trusses or joists  24  that are located between floors or levels of the wood or metal frame  23 . 
     Accordingly, embodiments of the fall protection system can be portable between floors of a building, as each floor of the building is being framed and constructed. In some embodiments of a method of using a fall protection system, the fall protection system can be installed on an initial floor or level of a frame of building, providing flexibility and extensibility to fall protection system  101 . On that level, the fall protection system can provide fall protection for workers ( FIG. 1A ) that work at the top  27  of the wood or metal frame  23 . When fall protection is no longer required or desired at that level of construction (e.g., framing is complete), and a next level of the building is ready to be added on top of that level, the fall protection system can be uninstalled from that level. The fall protection system can then be relocated to the next level and installed there, above the initial level. This installation and uninstallation sequence can be repeated until a top floor, or a roof structure is added to the building. 
     According to various embodiments, the individual components of fall protection system  101  are constructed from metal (for example, steel or aluminum) tubing, or composite materials, making them relatively lightweight and portable. As used herein, the term “lightweight” encompasses weights which can be lifted and positioned for assembly by one or two workmen. According to various embodiments, the components of fall protection system  101  can assembled and disassembled by only one user (i.e., a single user) with components that are readily manipulated by the single user and formed into an assembly, and with commonly available hand tools (for example, socket wrenches, screwdrivers, or hex keys). According to certain embodiments, the total weight of fall protection is minimal, relative to that of unfinished structure  21 , and can be supported through the natural bearing capacity of the frame of unfinished structure  21 . According to various embodiments, fall protection system  101  is provided as a kit for construction safety. Accordingly, the single user can manually transport, install, uninstall and then further transport and install the kit at an upper level. In some versions, the total kit weight can be in a range of about 25 pounds to about 75 pounds. In contrast, certain existing fall protection systems are much heavier and require a machine (such as a forklift) for transportation as well as installation. 
     As described herein, certain embodiments of fall protection system  101  configured to be coupled to the frame (also referred to herein as framing) of unfinished structure  21 , such as at a residential or light commercial construction site. The framing can include a support structure (i.e., the ground or the floor); lower sole plates, upper top plates, and a plurality of vertical studs extending between the upper and lower plates. The lower and upper plates can be coupled at corners of the frame. Versions of the frame can include joists and/or joist trusses, as well as roof trusses or rafters, as is known in the art. In additional or alternative embodiments, the frame may have other configurations. 
     The fall protection system can include a first fall protection device (e.g., tower) and a second fall protection device. The first and second fall protection devices can be the same or different. Accordingly, the description of one of the first and second fall protection devices can apply to both. The various components of the towers of the fall protection system can be moved or slide relative to each other to adjust the overall length. Likewise, the first and second fall protection devices can further include one or more diagonal, auxiliary support members. 
     Embodiments of the first fall protection device can be positioned adjacent to one portion (i.e., a corner) of the frame and the second fall protection device can be positioned adjacent another portion (i.e., another corner) of the frame. In particular, the first and second fall protection devices can extend along a vertical elevation of the frame adjacent the corners, while the stanchions extend above them. A first end of one lifeline can be secured to the stanchion of the first fall protection device, and a second end of the lifeline can be coupled to the stanchion for the second fall protection device. The lifeline extends between the first and second fall devices. In this way, a user couples to the lifeline such that, in the event of a fall, the user is captured by the lifeline and fall protection system and the probability of injury is reduced. 
     In other embodiments of a method of using the fall protection system, a user can position the first fall protection device adjacent to the frame, secure the base of the first fall protection device to the support structure, and secure the mount plate of the first fall protection device to a portion of the frame. The user also can couple the first end of the lifeline to the stanchion of the first fall protection device. The user can further position the second fall protection device adjacent to the frame, secure the base of the second fall protection device to the support structure, and secure the mount plate of the second fall protection device to another portion of the frame. The user can further couple the first end of the lifeline of the second fall protection device to the stanchion. 
     Positioning the second fall protection device can include positioning the second fall protection device at a desired distance from the first protection device. Additionally, securing the mount plate of each of the first and second fall protection devices to the frame can include securing each mount plate at a distance of 8 feet, 9 feet, or 10 feet from the respective base. The fall protection system is shown and described as being used at a residential or light commercial construction site. It is, however, within the scope of this disclosure that the fall protection system may be used at other types of construction sites as well. 
     In some particular examples, the fall protection system can be designed for use where the total weight of the supported user and equipment (e.g., tools) is 310 pounds or less, or up to 420 pounds under ANSI Z359 series using proper harness(es) and lifeline(s). The system can use exterior and/or interior wood or metal-framed building corners, as well as an intermediate stanchion using either exterior or interior wall surfaces. Versions of the corner brackets and intermediate brackets can use a sliding collar configuration. The bottom bracket can have a closed bottom section to limit the stanchion from going through the collar. The upper bracket can have an open collar, allowing the stanchion to extend through the collar. 
     Certain embodiments of fall protection system  101  are designed to interface with and be dimensionally compatible with wood or metal frame construction using standard construction techniques, such as construction standards wherein studs are on 16-inch centers or less. Further examples of standard construction dimensions with which embodiments of fall protection system  101  are structurally and dimensionally compatible include wood framing using Number 3 SYP or better, or Spruce Pine Fir (SPF) material. According to various embodiments, fall protection system  101  is configured to be attachable to metal framing, which can include commonly utilized cold rolled metal studs and track materials. The fall protection system can be mounted either external to the building, reducing interference between the system and the framing operation(s), or internally. When the fall protection system is mounted on the exterior of the building for use by (for example) floor joist crew, it also can be used by the floor decking crew for their edge fall protection. Further, the fall protection system can be used by the wall framing crew while they build and install the exterior wall units of the building, such that the exterior wall units then become support for their fall protection or negate the need for additional fall protection. 
     While certain embodiments according to this disclosure have heretofore been described with reference to systems using mount plates designed specifically to attach a slip sleeve of a lifeline tower to one of an inside corner, an outside corner or a flat surface of a structure under construction, the present disclosure is not so limited. In some embodiments according to this disclosure, a multi-piece or “universal” mount plate, which can be configured to connect a lifeline tower to any of an inside corner, an outside corner or a flat surface of a structure under construction, may be used. 
       FIGS. 9A through 9C  (collectively, “ FIG. 9 ”) illustrate a first example of a multi-piece, or “universal” mount plate  900  according to various embodiments of this disclosure. For convenience of cross-reference, elements of mount plate  900  which are visible in more than one of  FIGS. 9A-9C  are numbered similarly. 
     Referring to the non-limiting example of  FIG. 9 , a multi-piece mount plate  900  is shown in the figures. As will be discussed herein, multi-piece mount plate can be configured to connect a slip sleeve of a lifeline tower (for example, upper slip sleeve  141 ) to one or more of an inside corner, an outside corner or a flat surface of a structure (for example, wood or metal frame  23 ). As shown in the figure, multi-piece mount plate  900  comprises a first wing  901   a  and a second wing  901   b , wherein first wing  901   a  and second  901   b  are formed from a section of material (for example, stamped steel sheet) of sufficient strength to support the loads imparted by a lifeline tower passing therethrough, and the sheer and compressive loads produced by fasteners  999   a - f  anchoring multi-piece mount plate  900  to a structure. First wing  901   a  comprises a first body portion  905   a  and second wing  901   b  comprises a second body portion  905   b , wherein each of first body portions  905   a  and  905   b  are configured to be perpendicular to a slip sleeve  997  of a lifeline tower when the multi-piece mount plate  900  is in use and attached to a structure. Referring to the non-limiting example of  FIG. 9 , first wing  901   a  further comprises a first flange  910   a , which is perpendicular to first body portion  905   a . Similarly, in this example, second wing  901   b  comprises a second flange  910   b , which is perpendicular to second body portion  905   b . As shown in the illustrative example of  FIG. 9 , each of first flange  910   a  and second flange  910   b  comprises one or more mounting holes (for example, mounting holes  911   a  and  911   b ) through which fasteners (for example, screws, lag bolts or nails) to connect mount plate  900  to a structure pass. 
     Referring to the illustrative example of  FIG. 9 , mount plate  900  comprises a through hole  915 , which defines a space proportioned to accommodate a slip sleeve  997  of a lifeline tower according to various embodiments of this disclosure. According to various embodiments, through-hole  915  is formed by holes formed in both of first body portion  905   a  and second body portion  905   b . Depending on embodiments, through hole  915  may be shaped as a regular polygon (for example, configured to fit a square or hexagonal slip sleeve). In some embodiments, through hole  915  may be shaped as an irregular polygon (for example, to accommodate a slip sleeve with a rectangular cross-section). In various embodiments, through hole  915  has a circular or an oval shape. 
     According to various embodiments, when in use, second wing  901   b  is configured to sit on top of first wing  901   a , such that first flange  910   a  and second flange  910   b  define an angle (for example, 90 degrees in the case of an inside corner, 180 degrees in the case of a flat surface, or 270 degrees in the case of an outside corner) which is complementary to the portion of the structure to which mount plate  900  is to be attached. In some embodiments, the angle between first flange  910   a  and second flange  910   b  is set by the position of an indexing protrusion  920  relative to one or more indexing holes  925 . In the explanatory example of  FIG. 9 , indexing hole  925  is square shaped and coaxial with through-hole  915 . Similarly, indexing protrusion  920  is a square shaped and coaxial with through-hole  915 . In this example, the relative positions of first flange  910   a  and second flange  910   b  are indexed by the corners of square indexing hole  925 , such that, when second wing  901   b  is placed on top of first wing  901   a , first flange  910   a  and second flange  910   b  define one of a 90-degree angle, a 180 degree angle, a 270 degree angle or a 360 degree angle. 
     While not shown in  FIG. 9 , in certain embodiments, indexing hole  925  and indexing protrusion  920  are not coaxial with the through-hole  915  through which the slip sleeve of the lifeline tower passes through mount plate  900 . In some embodiments, indexing protrusion  920  comprises a pin or other protrusion disposed on the face of first body portion  905   a , and a plurality of indexing holes are provided on second body portion  905   b  corresponding to one or more installation angles for first flange  910   a  and second flange  910   b . In some embodiments (for example, where through hole  915  is circular and does not have corners to provide natural indexing positions), providing indexing protrusion  920  and indexing holes  925  may be advantageous. 
     According to various embodiments, one or more of first wing  901   a  or second wing  901   b  is provided with a second through-hole  925 , through which a cotter pin, grub screw or other fastener can pass through the hole and a corresponding hole in the slip sleeve of the lifeline tower to provide vertical support for mount plate  900 . 
       FIGS. 10A-10C  (collectively, “ FIG. 10 ”) illustrate three views of a second example of a multi-piece or “universal” mount plate  1000  according to various embodiments of this disclosure. For convenience of cross-reference, elements of mount plate  1000  which are visible in more than one of  FIGS. 10A-10C  are numbered similarly. 
     Referring to the non-limiting example of  FIG. 10 , in certain embodiments, mount plate  1000  comprises a first wing  1001   a  and a second wing  1001   b . According to various embodiments, each of first wing  1001   a  and second wing  1001   b  are constructed of a material which can resist loads imparted by a slip sleeve  1099  of a lifeline tower as well as loads imparted by fasteners (for example, fastener  1097 ) attaching mount plate  1000  to a portion of a structure (for example, wood or metal frame  23 ). Suitable materials for first wing  1001   a  and second wing  1001   b  include, without limitation, stamped steel sheet, stamped or forged aluminum or forged steel. As shown in the illustrative example of  FIG. 10 , first wing  1001   a  comprises a first body portion  1005   a , which, when mount plate is in use, is substantially perpendicular to slip sleeve  1099 . Further, as shown in  FIG. 10 , first wing  1001   a  further comprises a first flange  1010   a  that is perpendicular to first body portion  1005   a . According to various embodiments, first flange  1010   a  includes one or more mounting holes (for example, mounting hole  1011   a ), through which fasteners, such as nails, screws or lag bolts can pass to anchor first wing  1001   a  to a structure. 
     According to various embodiments, second wing  1001   b  comprises a second body portion  1005   b , which, when mount plate is in use, is substantially perpendicular to slip sleeve  1099 . Further, as shown in  FIG. 10 , second wing  1001   b  further comprises a second flange  1010   b  that is perpendicular to second body portion  1005   b . According to various embodiments, second flange  1010   b  includes one or more mounting holes (for example, mounting hole  1011   b ), through which fasteners, such as nails, screws or lag bolts can pass to anchor second wing  1001   b  to a structure. 
     Referring to the non-limiting example of  FIG. 10 , first body portion  1005   a  is pivotably connected to second body portion  1005  through a pivot  1015 . According to some embodiments, pivot  1015  comprises an annular pivot, such as used in a swivel plate (sometimes also referred to as a “lazy Susan”). In some embodiments, pivot  1015  comprises a section of circular material with top and bottom flanges, which allows first wing  1001   a  and second wing  1001   b  to rotate relative to each other, but generally prevents first wing  1001   a  and second wing  1001   b  from moving relative to one another along an axis of rotation of pivot  1015 . In this way, pivot  1015  allows first flange  1010   a  and second flange  1010   b  to be positioned at a range of angles relative to each other. In some embodiments, pivot  1015  allows first flange  1010   a  and second flange  1010   b  to pivot between a range of 90 and 270 degrees relative to each other, thereby allowing mount plate  1000  to be affixed to inside right angles, flat surfaces and outside right angles. 
     According to various embodiments, mount plate  1000  further comprises a through-hole  1020  which is configured to accommodate slip sleeve  1099  of a lifeline tower. In some embodiments, through-hole  1020  is coaxial with an axis of rotation of pivot  1015 , such as shown in  FIG. 10 . Accordingly, in some embodiments, pivot  1015  comprises an internal section  1017  which is configured to accommodate an external profile of the lifeline tower. In some embodiments, internal section  1017  may be a removable insert, so that multiple sizes and shapes of lifeline tower (for example, square and circular sections) can be accommodated. 
     While not shown in  FIG. 10 , according to various embodiments, through hole  1020  is not co-axial with an axis of rotation of pivot  1015 . For example, in some embodiments, through hole  1020  may only pass through one of first wing  1001   a  and second wing  1001   b . Alternatively, in some embodiments, a through-hole  1020  may be provided in each of first wing  1001   a  and second wing  1001   b , to permit mount plate to be attached to two lifeline towers. 
     This written description uses examples to disclose the embodiments, including the best mode, and also to enable those of ordinary skill in the art to make and use the invention. The patentable scope is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims. 
     Note that not all of the activities described above in the general description, or the examples are required, that a portion of a specific activity may not be required, and that one or more further activities may be performed in addition to those described. Still further, the order in which activities are listed are not necessarily the order in which they are performed. 
     In the foregoing specification, the concepts have been described with reference to specific embodiments. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the invention as set forth in the claims below. Accordingly, the specification and  FIGS. 1-10C  are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of invention. 
     It may be advantageous to set forth definitions of certain words and phrases used throughout this patent document. The term “communicate,” as well as derivatives thereof, encompasses both direct and indirect communication. The terms “include” and “comprise,” as well as derivatives thereof, mean inclusion without limitation. The term “or” is inclusive, meaning and/or. The phrase “associated with,” as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, have a relationship to or with, or the like. The phrase “at least one of,” when used with a list of items, means that different combinations of one or more of the listed items may be used, and only one item in the list may be needed. For example, “at least one of: A, B, and C” includes any of the following combinations: A, B, C, A and B, A and C, B and C, and A and B and C. 
     Also, the use of “a” or “an” are employed to describe elements and components described herein. This is done merely for convenience and to give a general sense of the scope of the invention. This description should be read to include one or at least one and the singular also includes the plural unless it is obvious that it is meant otherwise. 
     The description in the present application should not be read as implying that any particular element, step, or function is an essential or critical element that must be included in the claim scope. The scope of patented subject matter is defined only by the allowed claims. Moreover, none of the claims invokes 35 U.S.C. § 112(f) with respect to any of the appended claims or claim elements unless the exact words “means for” or “step for” are explicitly used in the particular claim, followed by a participle phrase identifying a function. Use of terms such as (but not limited to) “mechanism,” “module,” “device,” “unit,” “component,” “element,” “member,” “apparatus,” “machine,” “system,” “processor,” or “controller” within a claim is understood and intended to refer to structures known to those skilled in the relevant art, as further modified or enhanced by the features of the claims themselves, and is not intended to invoke 35 U.S.C. § 112(f). 
     Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. However, the benefits, advantages, solutions to problems, and any feature(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential feature of any or all the claims. 
     After reading the specification, skilled artisans will appreciate that certain features are, for clarity, described herein in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features that are, for brevity, described in the context of a single embodiment, may also be provided separately or in any subcombination. Further, references to values stated in ranges include each and every value within that range.