Abstract:
An anchor-to-lanyard adjustable riser cable with a choke and bearing plate. The device is positioned between a roof truss and a safety anchor system to better distribute the weight of a roofer on the truss in the event the roofer falls. The bearing plate is configured to engage a portion of the truss and to distribute forces into this structural member, thereby leading to attenuation of those forces. The bearing plate is provided with a non-skid surface to resist movement of the same along the structural member. Guide channels are provided on the bearing plate to receive portions of the cable from the cable choke therethrough. The bearing plate aids in protecting the structural member from being damaged by a lanyard extending to the safety harness in response to forces generated by the falling roofer.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Technical Field 
         [0002]    This invention generally relates to safety systems. More particularly, the invention relates to a safety system for a roof anchor. Specifically, the invention relates to device that is engaged between a roof truss and a roof anchor safety system for distributing and attenuating the forces that would be applied to the truss and roof sheathing in the event of a roofer falling while being secured to the truss by a safety harness. 
         [0003]    2. Background Information 
         [0004]    There are a variety of roof anchor safety systems that are used by roofers to ensure their safety while they are working on a roof. The safety harness is worn on the body and is connected by a steel cable to an anchor that is temporarily or permanently mounted on some region of the roof truss system. Should the roofer slip or fall, the cable connected to the anchor will tend to prevent them from falling off the roof and being severely injured. 
         [0005]    One of the problems in previously known safety systems is that the anchor is typically mounted on the peak or on the opposite side of the truss from where the roofer is working. This means that the steel cable extending between the anchor and the safety harness lanyard worn by the roofer is typically fed over the wood that forms the peak of the roof truss and is in direct contact with the sheathing that forms the base of the roof between the trusses. Since the cable is made from steel, it can cause substantial damage to the truss peak and to the plywood sheets that are used as sheathing in the event that the roofer slips or falls. This damage is essentially caused as the steel cable slams with force into the wood or plywood when the cable connected to the safety harness lanyard suddenly has to bear the roofer&#39;s full weight. The impact of the cable can slice and splinter the wood or sheathing and potentially damage the structural integrity of the same. 
         [0006]    There is therefore a need in the art for an improved safety anchor system that will tend to distribute and attenuate the forces involved in the event of this type of accident and which will thereby tend to minimize the potential damage to the wooden components of the roof. 
       BRIEF SUMMARY OF THE INVENTION 
       [0007]    The present invention is an anchor-to-lanyard adjustable riser cable with a choke and bearing plate that is positioned between a roof truss and a safety anchor system for distributing and attenuating the forces that would be applied to the truss and roof sheathing in the event of a roofer falling while being secured to the truss by a safety harness. In addition, the device transfers the energy force from the bottom of the truss rafter and the anchor connector plate to the top of the truss rafter when an attached workman slips or falls from the roof. This force transfer is important, creating a direction of force that favorably compresses the peak truss rafter joint rather than causing a horizontal pulling force on the lower portion of the truss connector plate. The device thus better distributes a roofer&#39;s weight and attenuates forces generated by the roofer falling than would be the case if the roofer&#39;s safety harness was directly secured by a cable or lanyard to a roof anchor on the truss. The bearing plate is configured to engage a portion of the truss and is provided with a non-skid surface to resist movement therealong. The bearing plate distributes the forces over a wider region of the truss than if only a cable connected the truss and harness. The plate protects the truss and roof ridge from possible damage when the lanyard suddenly is pulled taut and also aids in protecting the sheathing on the opposite side of the roof ridge. The choke is used to adjust the riser length. 
         [0008]    The device of the present invention does not aid the anchor system in arresting the fall of the roofer. It does, however, offer a measure of protection to the structural members of the roof in the event of a roofer&#39;s fall so that those structural members remain capable of performing as intended for the useful life of the building. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0009]    Preferred embodiments of the invention, illustrated of the best modes in which Applicant contemplates applying the principles, are set forth in the following description and are shown in the drawings and are particularly and distinctly pointed out and set forth in the appended claims. 
           [0010]      FIG. 1  is a perspective view of a building showing a roof truss having an anchor plate engaged therewith and showing a force distribution and attenuation device in accordance with the present invention engaged with the anchor plate; 
           [0011]      FIG. 2  is an enlarged front view of the peak of the roof truss showing the anchor plate and a first embodiment of the force distribution device in accordance with the present invention; 
           [0012]      FIG. 3  is a rear perspective view of the force distribution device and showing a first embodiment of a bearing plate utilized therein; 
           [0013]      FIG. 4  is a rear perspective view of bearing plate; 
           [0014]      FIG. 5  is a front perspective view of the bearing plate; and 
           [0015]      FIG. 6  is a side view of the force distribution device shown engaged with a clip and a portion of a lanyard that is connectable to a safety harness; 
           [0016]      FIG. 7  is a top perspective view of a second embodiment of a force distribution device for a roof anchor safety system in accordance with the present invention shown engaged on a truss and including a second embodiment of a bearing plate utilized therein; 
           [0017]      FIG. 8  is a top perspective view of the second embodiment of the bearing plate shown engaged on the roof truss; 
           [0018]      FIG. 9  is a top perspective view of the bearing plate of  FIG. 8 ; 
           [0019]      FIG. 10  is a bottom perspective view of the bearing plate of  FIG. 8 ; 
           [0020]      FIG. 11  is a side view of the bearing plate of  FIG. 8 ; 
           [0021]      FIG. 12  is a top perspective view of a third embodiment of a force distribution device for a roof anchor safety system in accordance with the present invention shown engaged on a truss and including a third embodiment of a bearing plate utilized therein; 
           [0022]      FIG. 13  is a top perspective view of the third embodiment of the bearing plate; 
           [0023]      FIG. 14  is a perspective view of a building showing the use of a separator bar for securing a portion of a safety harness lanyard to two force distribution devices of the type illustrated in  FIG. 13 ; and 
           [0024]      FIG. 15  is a top view of a portion of a building roof showing the separator bar engaged with the two force distribution devices. Similar numbers refer to similar parts throughout the drawings. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0025]    Referring to  FIG. 1  there is shown a building  10  having left and right side walls  12 ,  14  and a roof  16  that is being constructed disposed there between. Roof  16  is constructed from a plurality of roof trusses  18 , two of which are illustrated in this figure, and sheathing  20  which consists of a plurality of sheets of plywood that are secured to trusses  18 . Although not illustrated herein, roof shingles or other materials will ultimately be applied over sheathing  20 . 
         [0026]    Each roof truss  18  is comprised of a plurality of wood rafters  22  that are secured together by a plurality of steel plates  24 . In particular, roof truss  18  includes an anchor plate  26  that is engaged with rafters  22  adjacent the peak  28 . Anchor plate  26  is preferably a plate such as those disclosed in U.S. Pat. Nos. 7,380,373 and 7,832,153 issued to the present inventor. 
         [0027]    As shown in  FIG. 2 , anchor plate  26  comprises a body  30  that is secured to rafters  22  by a plurality of projections  32  extending outwardly from a rear face of plate  26  and driven into the wood of the rafters. Plate  26  defines one or more holes  34  therein for securement of a safety anchor system to truss  18 . For the sake of clarity, only a portion of a clip  60  and a lanyard  62  that would normally be attached to a safety harness or to a cable attached to a safety harness, are illustrated in  FIGS. 1-6 . 
         [0028]      FIGS. 1-6  show a first embodiment of a safety anchor system in accordance with the present invention. The safety anchor system includes a first embodiment of a force distribution device in accordance with the present invention and generally indicated at  36 . Force distribution device  36  further includes a first embodiment of a bearing plate in accordance with the present invention and generally indicated at  38 . 
         [0029]      FIGS. 7-11  illustrate a second embodiment of a safety anchor system in accordance with the present invention. The safety anchor system includes a second embodiment of a force distribution device in accordance with the present invention and generally indicated at  136 . Force distribution device  136  further includes a first embodiment of a bearing plate in accordance with the present invention and generally indicated at  138 . 
         [0030]    Referring now to  FIGS. 1-6 , force distribution device  36  is comprised of bearing plate  38  and a cable choke  40 . Bearing plate  38  is an L-shaped plated comprised of a first leg  42  and a second leg  44  that are disposed at an angle to each other. The angle is between 80° and 100° and preferably is 90°. Bearing plate  38  is manufactured from a strong, rigid material such as a metal, preferably steel. 
         [0031]    First leg  42  is a generally planar member having a first face  42   a  and a second face  42   b . First leg  42  defines a pair of spaced-apart apertures  46  therein that extend between first face  42   a  and second face  42   b . The planar member may be reinforced in the regions immediately surrounding apertures  46 . Second leg  44  is also a generally planar member having a first face  44   a  and a second face  44   b.    
         [0032]    In accordance with a specific feature of the present invention, first face  44   a  is provided with a non-skid surface  48  thereon. When force distribution device  36  is used, second leg  44  of bearing plate  38  is positioned in abutting contact with an upper surface  22   a  of one of the rafters  22  of truss  18 . Non-skid surface  48  is provided to improve the traction between bearing plate  38  and the upper surface  22   a  of truss rafter  22 . Non-skid surface  48  may be provided on first face  44   a  in a number of ways. Firstly, a plurality of grooves and ridges may be milled into the smooth original metal surface of first face  44   a . Alternatively, a compound such as a gripping polymer may be applied to first face  44   a  or an abrasive aggregate may be bonded to the metal of first face  44   a  with an adhesive. Any other suitable methodology and substances may be utilized or applied to first face  44   a  to produce the non-skid surface  48  and these other methodologies and substances are considered to fall within the scope of the present invention. Additionally, it should be understood that bearing plate  38  may be produced in shapes other than the L-shape illustrated herein without departing from the scope of the present invention provided that the differently configured bearing plate is able to distribute force over a greater area of rafter  22  than would be the case if a cable directly connected the safety harness on the roofer to the rafter. 
         [0033]    Preferably, the exterior edges  50  of one or both of first and second legs  42 ,  44  on bearing plate  38  are beveled or rounded so as to present a curved surface for contact by cable choke  40  and so as to reduce the possibility of bearing plate  38  cutting into the wood of rafter  22  and thereby damaging the same. 
         [0034]    Cable choke  40  preferably is a steel cable that is of sufficient strength so as not to break in the event of an impact due to a roofer falling. A free end of the cable  39  of cable choke  40  is threaded into a first one of the apertures  46  in bearing plate  38  in the direction indicated by arrow “A” in  FIG. 3 . Cable  39  is then threaded through the second one of the apertures  46  in bearing plate  38  from the direction indicated by arrow “B” in the same figure. The free ends of cable  39  are then looped back upon themselves and swages  52  are crimped adjacent these looped regions to secure cable choke  40  in place. Cable choke  40  thus includes a first looped region  54  and a second looped region  56  which are disposed adjacent second face  42   b  of first leg  42  of bearing plate  38 . A third looped region  58  is created between a portion of cable  39  and first face  42   a  of first leg  42 . It will be understood that bearing plate  38  is not fixedly secured to cable choke  40  and plate  38  is able to slide along cable  39  thereof. This enables the roofer to adjust the size of third looped region  58  and to correctly position bearing plate  38  on truss  22 . 
         [0035]    Force distribution device  36  is used in the following manner. A clip  60  secured to a lanyard  62  is engaged with third looped region  58  on force distribution device  36 . Although not shown herein, it is to be understood that lanyard  62  may itself be directly connected to a safety harness worn by the roofer or it may be connected to a cable that is secured to the safety harness. Bearing plate  38  is positioned on an upper surface  22   a  of an appropriate one of rafters  22 . The rafter is selected based on which side of the roof the roofer will be working. Bearing plate  38  should be positioned on the rafter disposed on the opposite side of the roof from the roofer. Non-skid surface  48  of bearing plate  38  is therefore positioned on upper surface  22   a  of rafter  22 A adjacent peak  28  and in such a way that third looped region  58  is disposed between the roofer and bearing plate  38 . Additionally, a first portion of cable  39  and first looped area  54  are positioned adjacent a first side wall of rafter  22 A and a second portion of cable  39  and second looped area  56  are positioned adjacent an opposed second side wall of rafter  22 A. An anchor plate pin  64  is inserted through one of the holes  34  in anchor plate  26  and the aligned first and second looped areas  54 ,  56  on cable choke  40 . (Pin  64  will be removed when it is desired to disengage force distribution device  36  from rafter  22 A.). The roofer secures his safety harness (not shown) to lanyard  62 . Non-skid surface  48  on bearing plate  38  aids in substantially immobilizing bearing plate  38  on rafter  22 A. Consequently, if the roofer should fall, the impact thereof will be transmitted from the harness (not shown) through lanyard  62  and clip  60  to force distribution device  36 . The force is then transmitted through cable choke  40  to bearing plate  38  and is thereby transmitted to a region of rafter  22 A in abutting contact with bearing plate  38 . The traction of bearing plate  38  on rafter  22 A afforded by non-skid surface  48  substantially prevents bearing plate  38  from sliding along rafter  22  under the impact of the force. Bearing plate  38  aids in distributing the force due to the impact more evenly into the upper surface  22   a  of rafter  22  and thereby aids in attenuating that force and reducing potential damage to rafter  22  and sheathing  20 . Additionally, at least a portion of the steel cable  39  of cable choke  40  is in contact with the metal of bearing plate  38  instead of being in direct contact with the wood of rafter  22 A. The metal disposed between cable  39  and the wood of rafter  22 A also substantially reduces the potential damage to rafter  22 A. As illustrated in  FIG. 2 , it is desirable that the edge  43  of bearing plate  38  be positioned above or aligned with peak  28  to further reduce the potential for damage to the same. 
         [0036]      FIGS. 7-11  show a second embodiment of a force distribution device in accordance with the present invention, generally indicated at  136 . Force distribution device  136  is also configured to be engaged with a truss anchor plate  126  mounted on a roof truss  118 . As with the previous embodiment, force distribution device  136  comprises a bearing plate  138  and cable choke  140 . Cable choke  140  is substantially identical to cable choke  40  and will therefore not be described in further detail. 
         [0037]    The features of bearing plate  138  are shown in greater detail in  FIGS. 9-11 . Bearing plate  138  comprises a generally L-shaped bracket having a first leg  142  and a second leg  144 . First and second legs  142 ,  144  are disposed at an angle relative to each other that is between 80° and 100° and preferably is 90°. Bearing plate  138  is manufactured from a strong, rigid material such as metal, preferably steel. 
         [0038]    First leg  142  of bearing plate  138  is a generally planar member having a first face  142   a  and a second face  142   b . In accordance with a specific feature of the present invention, first leg  142  is a generally U-shaped member comprising first and second arms  165 ,  167  that define a gap  166  there between. Gap  166  is sized and shaped to be complementary to the cross-sectional size and shape of at least a top region of a roof rafter  122 . First leg  142  defines a first portion  168   a  that will abut a first side surface (not shown) of rafter  122  when plate  138  is engaged therewith, a second portion  168   b  that will abut an upper surface  122   a  of rafter  122 , and a third portion  168   c  that will abut a second side surface  122   b  of rafter  122 . 
         [0039]    In accordance with yet another feature of the present invention, a pair of tubular conduits  170 ,  172  is welded or otherwise secured to second face  142   b  of bearing plate  138 . Tubular conduit  170  is provided on first leg  165  of bearing plate  138  and tubular conduit  172  is provided on second leg  167  thereof. Tubular conduits  170 ,  172  each define a bore  170   a ,  172   a  there through that is of any cross-sectional shape suitable to receive a portion of cable  139  of cable choke  140  there through. 
         [0040]    Second leg  144  of bearing plate  138  is a generally planar member having a first face  144   a  and a second face  144   b . In accordance with the present invention, first face  144   a  is provided with a non-skid surface and is adapted to abut upper surface  122   a  of truss rafter  122  when force distribution device  136  is engaged therewith. The non-skid surface provided on first face  144   a  is shown in  FIGS. 7-11  to be a plurality of alternating grooves  174  and ridges  176  that are milled into first face  144   a . The number of such grooves  174  and ridges  176  provided in first face  144   a  can vary. Preferably, the entire first face  144   a  is provided with grooves  174  and ridges  176  from adjacent first leg  142  to the edge  150   a  of second leg  144  as is illustrated in  FIG. 11 . Preferably, each groove  174  and ridge  176  extends substantially continuously from one side  151  of second leg  144  to the other side  153  thereof as is shown in  FIG. 10 . It will be understood, however, that regions of smooth metal may be interspersed along the length of each groove  174  and ridge  176  between sides  151 ,  153  or between adjacent grooves  174  and ridges  176  from first leg  142  to edge  150   a . It will further be understood that the provision of only one or two edges provided by such grooves  174  and ridges  176  will be able to generate sufficient skid-resistance to substantially immobilize bearing plate  136  on upper surface  122   a  in the event of a roofer falling. However, the greater the number of edges provided, the better the bearing plate  138  distributes the forces that are generated by the roofer falling and hanging from the anchor safety system. Consequently, an increased number of edges on first face  144   a  of bearing plate  136  will tend to lead to better protection of the wood surfaces of truss rafter  122  and sheathing  120  that might otherwise be damaged. 
         [0041]    In accordance with yet another feature of the present invention, second leg  144  of bearing plate  136  further includes a pair of spaced apart tubular conduits  178 ,  180 . Tubular conduits  178 ,  180  are welded or otherwise secured to second face  144   b  of bearing plate  138 . Tubular conduits  178 ,  180  each define a bore  178   a ,  180   a  there through that is configured to have a cross-sectional shape through which cable choke  140  may be threaded. Tubular conduit  178  is generally aligned with tubular conduit  170  and tubular conduit  180  is generally aligned with tubular conduit  172 . A first portion of cable  139  is threaded through tubular conduits  172  and  178  in a first direction, and a second portion of cable choke  140  is threaded through tubular conduits  174  and  180  in the opposite direction so that a looped region is formed in cable  139  as was the case with cable choke  40 . The free ends of cable  139  are then looped back onto themselves and swages  152  are used to secure the same. Cable choke  140  therefore includes first, second and third looped regions as was the case with cable choke  40 , except that in  FIG. 7 , only second and third looped regions  156  and  158  are shown. Bearing plate  138  is not fixedly secured to cable choke  140  and is able to slide along cable  139  so that the roofer can correctly position bearing plate  138  on rafter  122  and can pull sufficient cable  139  through tubular conduits  172 ,  174 ,  178 ,  180  to create the third looped section  158  of a sufficient size to attach his lanyard (not shown in these figures). 
         [0042]    Force distribution device  136  is used in the following manner. Bearing plate  138  is positioned on upper surface  122   a  of rafter  122  as illustrated in  FIG. 8  so that the top end of the rafter  122  is received in gap  166  in bearing plate  138 . Bearing plate  138  is moved downwardly so that second portion  168   b  of first leg  142  abuts upper surface  122   a  of rafter and the ridges  176  of first face  144   a  of second leg  144  contact upper surface  122   a  adjacent peak  128 . Bearing plate  138  has a longitudinal axis “Y” ( FIGS. 9 &amp; 11 ) that is generally aligned with a longitudinal axis of roof truss rafter  122 . An anchor pin  164  is inserted through one of holes  134  on anchor plate  126  and through the aligned first and second looped regions of cable choke  140 . This secures force distribution device and truss together. It should be noted that grooves  174  and ridges  176  are milled into first face  144   a  of bearing plate  138  in such a manner that they are disposed generally at right angles to longitudinal axis “Y”. Consequently, when bearing plate  138  is positioned on upper surface  122   a , the ridges  176  on first face  144   a  of bearing plate  138  are oriented substantially at right angles to the longitudinal axis of rafter  122  and are therefore able to generally immobilize the plate with respect to movement that is substantially directed along the longitudinal axis thereof. Additionally, first and second arms  165 ,  167  aid in generally reducing any lateral motion of bearing plate  138  in a direction substantially perpendicular to axis “Y”. Once again, force distribution device  136  and particularly bearing plate  138  thereof, helps distribute and attenuate the force exerted on truss rater  122  in the event of a fall by the roofer and thereby aid in preventing truss rafter  122  and sheathing  120  from being damaged. 
         [0043]      FIGS. 12 and 13  show a third embodiment of a force distribution device in accordance with the present invention, generally indicated at  236 . Force distribution device  236  is also configured to be engaged with a truss anchor plate  226  mounted on a roof truss  218 . As with the previous embodiment, force distribution device  236  comprises a bearing plate  238  and cable choke  240 . Cable choke  240  is substantially identical to cable choke  40  and will therefore not be described in further detail. 
         [0044]    Bearing plate  238  comprises a generally L-shaped bracket having a first leg  242  and a second leg  244 . First and second legs  242 ,  244  are disposed at an angle relative to each other that is between 80° and 100° and preferably is 90°. Bearing plate  238  is manufactured from a strong, rigid material such as metal, preferably steel. 
         [0045]    First leg  242  of bearing plate  238  is a generally planar member having a first face  242   a  and a second face  242   b . In accordance with a specific feature of the present invention, first leg  242  is a generally U-shaped member comprising first and second arms  265 ,  267  that define a gap  266  there between. Gap  266  is sized and shaped to be complementary to the cross-sectional size and shape of at least a top region of a roof rafter  222 . First leg  242  defines a first portion  268   a  that will abut a first side surface (not shown) of rafter  222  when plate  238  is engaged therewith, a second portion  268   b  that will abut an upper surface  222   a  of rafter  222 , and a third portion  268   c  that will abut a second side surface  222   b  of rafter  222 . 
         [0046]    In accordance with yet another feature of the present invention, a pair of apertures  290 ,  292  is defined in first leg  242  of bearing plate  238 . Aperture  290  is defined in first arm  265  and aperture  292  is defined in second arm  267 . Apertures  290 ,  292  extend between first and second faces  242   a ,  242   b  of first leg  242  and preferably are positioned adjacent the region  294  where first leg  242  is joined to second leg  244 , i.e., the apertures are positioned close to the corner of bearing plate  238 . Preferably, apertures  290 ,  292  are horizontally aligned with each other. 
         [0047]    Second leg  244  of bearing plate  238  is a generally planar member having a first face  244   a  and a second face  244   b . In accordance with the present invention, first face  244   a  is provided with a non-skid surface and is adapted to abut upper surface  222   a  of truss rafter  222  when force distribution device  236  is engaged therewith. The non-skid surface provided on first face  244   a  is substantially identical to the non-skid surface provided on first face  144   a  of bearing plate  138 . As such, the non-skid surface comprises a plurality of alternating grooves  274  and ridges  276  that are milled into first face  244   a . The possible variations in the grooves and ridges have been described with reference to bearing plate  138  and will therefore not be discussed further herein. It should be understood that other suitable non-skid surfaces may be provided on first face  244   a  without departing from the scope of the present invention. 
         [0048]    In accordance with yet another feature of the present invention, a pair of apertures  296 ,  298  is defined in second leg  244  of bearing plate  238 . Aperture  296  is defined adjacent a first edge  244   c  and extends between first and second faces  244   a ,  244   b  of first leg  244 . Aperture  296  is substantially longitudinally aligned with aperture  290  in first leg  242 . Aperture  298  is defined adjacent a second edge  244   d  of second leg  244  and extends between first and second faces  244   a ,  244   b . Aperture  298  is substantially longitudinally aligned with aperture  294  in first leg  242 . Aperture  296  is generally horizontally aligned with aperture  298 . 
         [0049]    A first portion of cable  239  of cable choke  240  is threaded through aligned apertures  290  and  296  in a first direction, and a second portion of cable choke  240  is threaded through aligned apertures  298 ,  294  in the opposite direction so that a looped region is formed in cable  239  as was the case with cable choke  40 . As illustrated in  FIG. 12 , the direction of threading of cable  239  is such that a portion of the cable  239  runs along second face  242   b  of each of the first and second arms  265 ,  267  and a portion of cable  239  abuts second face  244   b  of second leg  244 . This ensures that when a force is applied to bearing plate  238 , the cable  239  will force plate  238  downwardly into contact with upper surface  222   a  of rafter  222 . The free ends of cable  239  are looped back onto themselves after being threaded through apertures  290 ,  296 ,  298  and  294  and swages  252  are used to secure the same. Cable choke  240  therefore includes first, second and third looped regions as was the case with cable choke  40 , except that in  FIG. 12 , only second and third looped regions  256  and  258  are shown. Bearing plate  238  is not fixedly secured to cable choke  240  and is able to slide along cable  239  so that the roofer can correctly position bearing plate  238  on rafter  222  and can pull sufficient cable  239  through apertures  290 ,  296 ,  298 ,  294  to create the third looped section  258  of a sufficient size to attach his lanyard  260 . 
         [0050]    Force distribution device  236  is used in the following manner. Bearing plate  238  is positioned on upper surface  222   a  of rafter  222  as illustrated in  FIG. 12  so that the top end of the rafter  222  is received in gap  266  in bearing plate  238 . Bearing plate  238  is moved downwardly so that second portion  268   b  of first leg  242  abuts upper surface  222   a  of rafter and the ridges  276  of first face  244   a  of second leg  244  contact upper surface  222   a  adjacent the truss peak (not shown). Bearing plate  238  has a longitudinal axis (not shown) that is generally aligned with a longitudinal axis of roof truss rafter  222 . An anchor pin  264  is inserted through one of holes  234  on anchor plate  226  and through the aligned first and second looped regions of cable choke  240 . This secures force distribution device and truss together. It should be noted that grooves  274  and ridges  276  are milled into first face  244   a  of bearing plate  238  in such a manner that they are disposed generally at right angles to the longitudinal axis of bearing plate  238 . Consequently, when bearing plate  238  is positioned on upper surface  222   a , the ridges  276  on first face  244   a  are oriented substantially at right angles to the longitudinal axis of rafter  222  and are therefore able to generally immobilize the plate with respect to movement that is substantially directed along the longitudinal axis thereof. Additionally, first and second arms  265 ,  267  aid in generally reducing any lateral motion of bearing plate  238  in a direction substantially perpendicular to the longitudinal axis. Once again, force distribution device  236  and particularly bearing plate  238  thereof, helps distribute and attenuate the force exerted on truss rater  222  in the event of a fall by the roofer and thereby aid in preventing truss rafter  222  and sheathing  220  from being damaged. 
         [0051]    Force distribution device  236  has been found to be adaptable to a range of different roof pitches that might be encountered by a roofer. Device  236  has a lower center of gravity than devices  36  and  136  and therefore tends to hold better on roof trusses having a steeper pitch. 
         [0052]      FIGS. 14 and 15 , illustrate how the device of the present invention may be used in tandem as a pair to better secure a roofer in certain situations. In this instance a spreader bar  302  is operationally engaged with two or more force distribution devices  236 . Bearing plates  238  of devices  236  are engaged on adjacent roof trusses  222 . Bar  302  is positioned between two separate riser cable chokes  240  and is attached to each riser cable choke  240  by a suitable fastener  304 , thereby incorporating the force resistance capacity of two truss anchor plates (not shown). The safety harness lanyard  260  is secured to bar  302 . The connected safety harness lanyard  260  is thereby able to deliver a greater measure of safety to the worker in the event of a fall arrest. The spreader bar  302  can be located directly on the roof ridge or off the roof ridge. 
         [0053]    It should be noted that one of the advantages of the present invention is that the force geometry relating to securing a lanyard to a roof anchor has been improved over devices that were previously known. In particular, the force geometry is improved by cabling the resistance from under the rafter to the top of the rafter through the bearing plate. Devices  36 ,  136  and  236  transfer the energy force from the bottom of truss rafter  22 ,  122 ,  222  and anchor plate  26 ,  126 ,  226  to the top of truss rafter  222  when an attached roofer slips or falls from the roof. This force passes through the slide adjustable bearing plate  38 ,  138 ,  238 . The force transfer is important in that it creates a direction of force that favorably compresses the peak truss rafter joint (indicated at  300  in  FIG. 12 ) together, thus strengthening rafter  222  rather than causing a horizontal pulling force on the lower portion of truss anchor plate  226 . 
         [0054]    In the foregoing description, certain terms have been used for brevity, clearness, and understanding. No unnecessary limitations are to be implied therefrom beyond the requirement of the prior art because such terms are used for descriptive purposes and are intended to be broadly construed. 
         [0055]    Moreover, the description and illustration of the invention are an example and the invention is not limited to the exact details shown or described.