Abstract:
A mobile mount for attachment of a fall arrest system is provided for example for aircraft and includes a base carried on ground wheels and a support which is adjustable in height upstanding from the base and an arm cantilevered over the base. At least one receptacle is mounted on the arm of the support at a position located over the base for attachment to a personal fall arrest system including a harness for one or more persons, with the receptacle, base and support being designed and arranged to receive a loading from the personal fall arrest system sufficient to accommodate a fall of the person from the elevated structure.

Description:
[0001]     The present invention relates a mobile mount for attachment of a fall arrest system.  
       BACKGROUND OF THE INVENTION  
       [0002]     Full protection of operators working in a situation where a fall can take place over a sufficient distance to cause injury or death is becoming generally required in most industries. Many arrangements are provided for mounting an anchor post on a structure adjacent the worker so that a personal fall arrest system can be attached to the anchor.  
         [0003]     Such personal fall arrests systems include a harness together with a cable system for attachment to the harness and to a suitable anchor where the cable system can be paid out to allow the worker to move to a required location but the cable system arrests any fall within a short distance. Such devices are well known and commercially available and many different designs have been proposed.  
         [0004]     In most cases the structure itself provides or has attached a suitable anchoring post so that the relatively high loading necessary can be readily provided by a simple post rigidly attached to the structure.  
         [0005]     In the interior buildings, such anchors can be mounted on a rail which allows the anchor to slide longitudinally along a track attached to the rail.  
         [0006]     However some structures are unsuitable for attachment of an anchor post or have been designed without the possibility of attachment of an anchor post so that operators in this environment are often unprotected against fall. In a particular area where this is problematic is in that related to aircraft where aircraft design does not lead to the suitability of attachment of mounting posts. Up until now, therefore, operators working in this environment have remained unprotected with the potential of serious injury or death.  
       SUMMARY OF THE INVENTION  
       [0007]     According to a first aspect of the invention there is provided an apparatus comprising:  
         [0008]     a base carried on ground wheels for movement over a ground surface to an elevated structure on which one or more persons is intended to work;  
         [0009]     a support upstanding from the base having an upstanding support portion extending from the base to an elevated position above the base and an arm assembly extending from the upstanding support portion to a position cantilevered over the base;  
         [0010]     the upstanding support portion being adjustable in height from the base;  
         [0011]     and at least one receptacle mounted on the arm assembly of the support at a position located over the base for attachment to a personal fall arrest system including a harness for said one or more persons;  
         [0012]     the receptacle, base and support being designed and arranged to receive a loading from the personal fall arrest system sufficient to accommodate a fall of the person from the elevated structure.  
         [0013]     Preferably there are at least two receptacles carried on the arm assembly each for receiving the personal fall arrest system of a respective one of two separate persons.  
         [0014]     Preferably the or each receptacle is mounted so as to allow side to side movement of the receptacle relative to the base.  
         [0015]     Preferably the base includes a hitch by which the base can be moved to the elevated structure by a towing vehicle.  
         [0016]     Preferably there is provided a ladder carried on the support for the person to ascend to the elevated structure from the ground, which ladder can extend with the extension of the upstanding support portion.  
         [0017]     Preferably there is provided a platform at a top of the ladder extending from the top of the ladder outwardly over the base.  
         [0018]     Preferably the support arm assembly is arranged such that the at least one receptacle is cantilevered generally over a mid line of the base.  
         [0019]     In one arrangement, the or each receptacle is carried on a rail mounted on the support arm assembly so as to extend along midline of base.  
         [0020]     Preferably the or each receptacle is designed to receive a load of at least 1800 pounds.  
         [0021]     Preferably there are two receptacles and the support arm assembly carrying the two receptacles is arranged to support a load of at least 2000 pounds.  
         [0022]     Preferably the or each receptacle comprises a loop for receiving a hook of the personal fall arrest system.  
         [0023]     Preferably the upstanding support portion is arranged along one side of the base and the support arm assembly extends from the upstanding support portion so as to be cantilevered therefrom across the base.  
         [0024]     In one arrangement, the upstanding support portion comprises a pair of posts spaced apart along the side of the base.  
         [0025]     Preferably the upstanding support portion includes a cross rail between the posts.  
         [0026]     In one arrangement, there is provided a ladder between the posts for the person to ascend to the elevated structure from the ground.  
         [0027]     In one arrangement, the upstanding support portion includes a ladder with side rails and transverse rungs for the person to ascend to the elevated structure from the ground and wherein there is a post attached to an upper end of each side rail with the at least one receptacle mounted on a top of at least one of the posts.  
         [0028]     Preferably the post is inclined forwardly of an upper end of the side rail to cantilever the receptacle in front of the ladder.  
         [0029]     Preferably there is provided a platform between rails at the top of the ladder for the person to step onto the elevated structure.  
         [0030]     In another arrangement, there are two ladders each including side rails and transverse rungs for the person to ascend to the elevated structure from the ground and wherein there is a post attached to an upper end of each side rail with a transverse beam extending between the ladders and carrying the at least one receptacle. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0031]     On embodiment of the invention will now be described in conjunction with the accompanying drawings in which:  
         [0032]      FIG. 1  is an isometric view of the first embodiment according to the present invention.  
         [0033]      FIG. 2  is an isometric view of the embodiment of  FIG. 1  modified to incorporate a ladder and platform by which the operator can raise to the elevated structure.  
         [0034]      FIG. 3  is an isometric view of a second embodiment according to the present invention.  
         [0035]      FIG. 4  is an isometric view of a modified version of the embodiment of  FIG. 3  incorporating two of the components of  FIG. 3  connected together. 
     
    
     DETAILED DESCRIPTION  
       [0036]     In  FIG. 1  is shown a first embodiment according to the present invention which includes a base  10  and a support  11  for supporting anchors or receptacles  12  and  13  at a raised position above the base.  
         [0037]     The base comprises a pair of side rails  14  and  15  extending forwarding from a rear frame structure  15 . At the outer end of each side rail is provided a ground engaging wheel  16  for rolling over the ground supporting the base.  
         [0038]     The frame  15  comprises a pair of rails  17  and  18  which are parallel and generally at right angles to the side rails  14  and  14 A. The rails  17  and  18  are parallel and interconnected by a number of cross members  19  which hold the rails parallel. The rails  14  and  14 A are attached to respective ends of the rails  17  and  18  so as to form a rigid structure. Some of the cross members  19  extend outwardly beyond the rails  17  and  18  and provide a support for a ground wheel  20  which co-operates with a ground wheel  16  in supporting the base for movement across the ground. The number of ground wheels and arrangement of ground wheels depends upon the weight to be supported and the type of ground wheel to be used. The base provides a relatively wide area for support over the ground to prevent toppling of the structure when load is applied.  
         [0039]     At opposite ends of the frame  15  is provided a pair of upstanding posts  22  and  23  which form a part of the support  11 . The upstanding posts are formed in two sections including upper portions  22 A and  23 A which are slidable vertically relative to the lower portions  22 B and  23 B. Suitable mounting using bearings can be provided between the portions to allow the vertical sliding movement required to elevate the upper section relative to the lower section. A cross member  24  connects the upper end of the lower portions  22 B and  23 B to retain the structure rigid. A similar cross member  25  is provided across the top of the upper portions  22 A and  23 A to maintain the upper section rigid. The upper section is raised relative to the lower section by chains  26  and  27  carried on lower pulleys  27  and  28  respectively operated by manually rotatable handle  29  attached to a shaft  30 . The shaft  30  extends between the two pulleys  27  and  28  so the rotation of the handle  29  pulls the chains  26  and  27  over an upper pulley  31 ,  32  respectively at the top of the respective posts portions  22 B and  23 B so as to pull on the lower end of the upper portions  22 A and  23 A pulling them upwardly along the slide mounting indicated at  34 .  
         [0040]     Thus the upright portion of the support  11  defined by the posts and the cross members can be raised and lowered to a required height. At the top of the upper portion of the posts is provided a cantilever arm section generally indicated at  35  forming part of the support  11 . The cantilever arm structure comprises a rail  36  parallel to the cross beams  25  and  24  and cantilevered outwardly therefrom on support rails  37 ,  38 ,  39  and  40 . The rails  38  and  40  form a brace at an angle to the rails  37  and  39  thus maintaining the rail  36  at a position approximately midway across the base from the frame  15  towards the wheels  16 .  
         [0041]     The rail  36  is formed by a structural tube together with a transport track attached to the underside of the structural tube so the track carries a pair of trolleys  41  and  42  which can slide along the track  43  independently of one another. Each trolley carries a respective one of the anchors  12 ,  13 .  
         [0042]     Thus the operator shown in  FIG. 1  can be wheeled to a required location at an elevated structure with the rail  36  supported at a position above the elevated structure by any necessary adjustment of the height of the support. The location of the rail  36  over the elevated structure can be obtained by moving the base on the wheels to the required position relative to the elevated structure. The arrangement as shown is particularly suitable for location over the wing of an aircraft with the rail  36  at a position approximately head height above the operator standing on the wing. Thus the base is located under the wing with the rail  36  above the wing.  
         [0043]     The structure is designed and arranged to provide sufficient loading so that the anchors can receive the full force obtained by an operator falling from the elevated structure.  
         [0044]     In practice it has been determined that the necessary loading which the anchor must accommodate is of the order of 1800 lbs. for a single operator and either 2000 lbs. or 3000 lbs. for two operators depending upon the jurisdiction where the standards are in force. Thus the anchor is not merely an anchor location but must provide sufficient strength so that the fall of a heavy operator potentially carrying heavy equipment and the impact of that fall on the personal fall arrest system can be applied to the anchor and through the anchor to the ground without damaging the structure or allowing the operator to fall beyond the intended position arrested by the fall arrest system.  
         [0045]     Turning now to  FIG. 2 , there is shown exactly the same structure as shown in  FIG. 1  together with the additional elements of a ladder  50 , a platform  51  and a hitch  52 . The ladder  50  comprises side rails  53  and  54  together with transverse rungs  55 . The ladder is formed of a lower section  56  and an upper section  57  which can extend at its lower section  56  by sliding along side rails at a coupling  58 . The upper end of the ladder is mounted on a cross beam  59  attached to the slides  34  by posts  60 . Thus the upper end of the ladder is attached to the upper part of the frame for elevation therewith so that elevation of the other part of the frame obtained by the operator rotating the handle  29  automatically acts to lift the upper end of the ladder relative to the lower end of the ladder. The lower end of the ladder is attached to a pair of extension pieces  62  and  63  which extend outwardly from respective ones of the cross members  19  of the frame  15 . Such cross members can be formed from a tube so that the lower part of the ladder includes a smaller tube inserted into the outer tube of the cross member  19  for readily attaching the ladder to the structure.  
         [0046]     Thus the lower end of the ladder is fixed and the upper extends with the support to the required height to allow the operator to climb the ladder to the required location. At the top of the ladder is provided the platform  51  which is cantilevered out from the rail  59  and may be supported by braces from the rail  25 . The platform provides a horizontal surface onto which the operator can step to transfer from the ladder to the horizontal surface and from the horizontal surface onto the structure to be worked upon. Alternatively the operator may remain on the platform to carry out the work while protected from falling by the fall restraint system provided by the anchors  12  and  13 . Hand rail  51 A can supplement the platform to allow the operator to stand while supported.  
         [0047]     Turning now to  FIG. 3 , an alternative embodiment is shown including a base  100  and a support  111  for anchors  112  and  113 . In this embodiment the base  100  is formed by cross beams  101  and  102  carrying ground wheels  103  together with longitudinal beams  104  and  105 . The wheels are suitable castor wheels or may alternatively be driven wheels for moving the base by powered operation.  
         [0048]     In this embodiment the support  111  is in the form of a ladder structure  114  with side rails  115  and  116  together with transverse rungs  117  and an upper platform  118 . The ladder structure is again formed in two pieces with an upper part  120  which can be raised relative to a lower part  121  by actuation of a manually operable chain lifting system  124 . Thus the upper parts of the rails of the ladder can slide upwardly to raise the platform  118  and the anchors  112  and  113  to a required height above an elevated structure to operated on. The lower part of the ladder is rigidly attached to the cross beam  103  and is supported by braces  125  and  126  extending downwardly to the longitudinal rails  104  and  105 . The lower end of the braces is attached to slide members  127  which can move longitudinally along the respective rails  104 ,  105  and carry a cross beam  128  which has stabilizing legs  129  at each end. Stabilizing legs can be moved down into engagement with the ground so as to transfer some loading from the base from the wheels to the legs to maintain the base at a required location.  
         [0049]     At the upper end of the rails  115  and  116  of the ladder is provided a tubular receptacle  130 ,  131  for a curved post  132  and  133  respectively which extends upwardly from the receptacle and forwardly beyond the end of the upper part of the ladder to the upper anchor  112 ,  113  respectively. Thus the anchors are cantilevered forwardly beyond the end of the ladder by the curvature of the posts  132  and  133 . Thus again the anchors  112  and  113  are located approximately over the midline of the base and a cantilevered over structure with the base located underneath the structure. Again this arrangement is particularly suitable for the wing of an aircraft where the base can be moved to a position beneath the wing with the platform moved up to the end of the wing and the anchors  112  and  113  located over the wing for the operator to transfer from the platform onto the wing for operations on the aircraft.  
         [0050]     In  FIG. 4  is shown an alternative arrangement which utilizes basically the structure of  FIG. 3  arranged in a pair of such structures connected together by cross members  140  and  141 . Thus each base  100  and each support  111  is provided at a position spaced transversely of the base frames and connected together at spaced positions by the rails  140  and  141 . At the top of the post  132  and  133  is provided a transverse rail  136  similar to the rail  36  which carries a track  137  and trolleys  138 . Each trolley is attached to a personal safety arrest system generally indicated at  145 . Thus the basic system shown in  FIG. 3  can be modified to provide an elongated structure to provide an elongated protection system along the full extent of the rail  136  which may be up to 30 feet in length so that a number of operators can be properly protected by personal fall arrest systems slidable along the rail  136  in its track  137 . The rail  136  can be removed from the posts  132  and  133  and the base  100  can be separated to provide two separate elements which can be used independently. The base structure in  FIG. 4  is slightly different in construction from that shown in  FIG. 3  in that the side rails extend at an angle outwardly and the wheels are attached to the ends of the side rails rather than to the ends of the cross rail  101  as shown in  FIG. 3 . It will be appreciated that different forms of base structure be designed with the intention that the structure merely provides sufficient ground engagement area to accommodate any side loads which occur as an operator falls to prevent the system from toppling and to maintain the rail  136  at its elevated position despite any direction of fall of one or more operators from the elevated structure.  
         [0051]     The structure shown in  FIG. 1  can also be extended by providing additional posts and increasing the length of the rails  24 ,  25  and  36 . Thus for example the basic rail  36  may be of the order of 20 ft. which should be increased to 30 ft. by providing an additional post to provide three such posts in a row.  
         [0052]     Since various modifications can be made in my invention as herein above described, and many apparently widely different embodiments of same made within the spirit and scope of the Claims without department from such spirit and scope, it is intended that all matter contained in the accompanying specification shall be interpreted as illustrative only and not in a limiting sense.