Abstract:
An apparatus for use in fall restraint anchoring of workers on an elevated location includes an upstanding post with at least one attachment loop at an upper end. The post is formed by plurality of coaxial cylindrical tubes each mounted as a sliding fit inside the next with each insert tube having a longitudinal groove co-operating with a projecting set screw on the outer tube so as to prevent relative rotation and to locate the limits of movement for aligning holes in the tubes for a locking pin. A jib portion includes a collar located on the smallest tube with a lower edge sitting on the upper edge of the next tube and extends upwardly and outwardly to a tether which extends to the attachment loop.

Description:
[0001]    This invention relates to a fall restraint anchoring post for use in attachment thereto of fall restraints for one or more persons working at a raised elevation on a location where the post is mounted.  
         BACKGROUND OF THE INVENTION  
         [0002]    In Canadian Application 2,179,248 published December 18 th , 1997 is disclosed a fall restraint anchoring system which can be used at an elevated location such as the top of a transformer where one or more workers is required to be tethered to an upstanding post by a harness and line to prevent accidental fall from the elevated location.  
           [0003]    Such harnesses together with the necessary line, pay-out system and shock absorption system are well known and are commercially available. Posts of the type generally shown in the above patent application have been commercially available for many years and are widely used. The post has at its upper end three rings which rotate around the longitudinal axis of the post and each carries a loop which can be attached to a respective one of the three workers individually attached to the post. Workers therefor can move around the post to the required location for there current function but if any one or all of the workers fall from the elevated location, they are supported by the posts, falling only a short distance before the line and harness halt there fall. The elevation of the post reduces the distance that the worker falls.  
           [0004]    It is often desirable that the post be collapsible from a retracted condition to the required extended condition for operation so that it can be transported and stored readily in the retracted condition. For this purpose the post is manufactured from square tubing with each portion slidable inside the next. This provides a relatively crude construction using relatively expensive square tubing.  
           [0005]    Further examples of devices of this general type are shown in U.S. Pat. No. 4,987,976 (Daugherty) assigned to Vermette Machine Company and issued January 29 th , 1991 and in U.S. Pat. No. 5,718,305 (Palmer) issued February 17 th , 1998.  
         SUMMARY OF THE INVENTION  
         [0006]    It is one object of the invention to provide an improved post construction which can be used to attach one or more workers as a fall restraint anchoring system.  
           [0007]    According to one aspect of the invention there is provided an apparatus for use in fall restraint anchoring comprising:  
           [0008]    a base member for mounting at a location where workers require to be restrained against falling;  
           [0009]    a post having a bottom mounting for attachment to the base member such that the post is supported in upstanding arrangement from the base member at the location;  
           [0010]    at least one attachment loop at an upper end of the post for connection to a fall restraint connection line of a worker;  
           [0011]    the post comprising a plurality of coaxial cylindrical tubes, each of circular cross-section, including a outer tube and an insert tube mounted as a sliding fit inside the outer tube for sliding movement longitudinally thereof for movement from an extended operating position to a retracted position, either the outer tube or the insert tube being attached to the bottom mounting;  
           [0012]    the outside surface of the insert tube having a groove formed longitudinally thereof extending only part way therealong so that the groove terminates at its upper end a position spaced from an upper end of the insert tube and so that the groove terminates at its lower end a position spaced from a lower end of the insert tube;  
           [0013]    and the outer tube having a projecting element at a fixed position thereon extending radially inwardly of the inside surface thereof so as to extend into the groove;  
           [0014]    the groove and the projecting element being arranged and located so as to limit movement of the insert tube relative to the outer tube so that the tubes are prevented from relative rotational movement and so that the insert tube is limited to movement only between said extended and retracted positions.  
           [0015]    Preferably the projecting element comprises a set screw.  
           [0016]    Preferably there is only a single groove and a single projecting element.  
           [0017]    Preferably the outer tube and the insert tube have holes therethrough arranged to be aligned in the extended position for receipt therethrough of a locking pin and wherein the groove and the projecting element are arranged so that the holes are properly aligned for receipt of the pin when the projecting element reaches the end of the groove.  
           [0018]    Preferably there is provided a clamping screw mounted on the outer tube so as to move a clamping end thereof radially of the outer tube and operable to clamp against the outer surface of the insert tube.  
           [0019]    Preferably the clamping screw is arranged on the outer tube at a position spaced 180 degrees angularly from the projecting element.  
           [0020]    Preferably the post includes a plurality of attachment loops at axially spaced positions on the post each arranged for rotation around the post about the axis of the post.  
           [0021]    Preferably there is provided a separate extension piece arranged to be mounted on an upper end of the post and extending upwardly therefrom and including a further attachment loop at its upper end.  
           [0022]    Preferably there is provided a second insert tube mounted as a sliding fit inside the insert tube for sliding movement longitudinally thereof for movement from an extended operating position to a retracted position; the outside surface of the second insert tube having a second groove formed longitudinally thereof extending only part way therealong so that the second groove terminates at its upper end a position spaced from an upper end of the second insert tube and so that the second groove terminates at its lower end a position spaced from a lower end of the second insert tube; and the insert tube having a second projecting element at a fixed position thereon extending radially inwardly of the inside surface thereof so as to extend into the second groove; the second groove and the second projecting element being arranged and located so as to limit movement of the second insert tube relative to the insert tube so that the tubes are prevented from relative rotational movement and so that the second insert tube is limited to movement only between said extended and retracted positions.  
           [0023]    Preferably the second groove is arranged at 180 degree angular spacing from the groove.  
           [0024]    Preferably there is provided a jib portion comprising:  
           [0025]    a collar surrounding the upper insert tube and mounted thereon as a sliding fit so as to be rotatable thereon about the axis of the post;  
           [0026]    the collar having a bottom abutment surface resting upon a top edge of the lower outer tube  
           [0027]    a jib member mounted on the collar so as to extend outwardly from the collar to one side of the post;  
           [0028]    the jib member being mounted on the collar for upward and downward pivotal movement about a horizontal axis;  
           [0029]    and a tether member extending from the jib member to the attachment loop for supporting the jib member at an angle inclined upwardly and outwardly from the collar.  
           [0030]    Preferably the collar includes two semi-cylindrical collar parts connected by a hinge on one side of the post and clamped at abutment surfaces on an opposed side of the post.  
           [0031]    Preferably the jib member includes at least one bracket for supporting a winch and a pulley at an outer end thereof over which a cable from the winch is guided to pass.  
           [0032]    Preferably the post includes a bottom tube, an uppermost tube and at least one intermediate tube all of which are slidable each into the next and wherein the collar is clamped onto the uppermost tube with its abutment surface resting against an upper edge of the intermediate tube.  
           [0033]    According to a second aspect of the invention there is provided an apparatus for use in fall restraint anchoring comprising:  
           [0034]    a base member for mounting at a location where workers require to be restrained against failing;  
           [0035]    a post having a bottom mounting for attachment to the base member such that the post is supported in upstanding arrangement from the base member at the location;  
           [0036]    at least one attachment loop at an upper end of the post for connection to a fall restraint connection line of a worker;  
           [0037]    the post comprising a plurality of coaxial cylindrical tubes, each of circular cross-section, including a lower outer tube and an upper insert tube mounted as a sliding fit inside the lower outer tube for sliding movement longitudinally thereof for movement from an upwardly extended position to a lower retracted position;  
           [0038]    and a jib portion comprising:  
           [0039]    a collar surrounding the upper insert tube and mounted thereon as a sliding fit so as to be rotatable thereon about the axis of the post;  
           [0040]    the collar having a bottom abutment surface resting upon a top edge of the lower outer tube  
           [0041]    a jib member mounted on the collar so as to extend outwardly from the collar to one side of the post;  
           [0042]    the jib member being mounted on the collar for upward and downward pivotal movement about a horizontal axis;  
           [0043]    and a tether member extending from the jib member to the attachment loop for supporting the jib member at an angle inclined upwardly and outwardly from the collar. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0044]    One embodiment of the invention will now be described in conjunction with the accompanying drawings in which:  
         [0045]    [0045]FIG. 1 is an isometric view from above and one side of a post assembly according to the present invention.  
         [0046]    [0046]FIG. 2 is an isometric view from above and the opposite side of the post assembly of FIG. 1.  
         [0047]    [0047]FIG. 3 is an isometric view of the post assembly of FIG. 1 including a jib portion mounted thereon.  
         [0048]    [0048]FIG. 4 is an isometric view of the jib portion of FIG. 3 from the opposite side.  
         [0049]    [0049]FIG. 5 is a cross sectional view along the lines  5 - 5  of FIG. 1.  
         [0050]    In the drawings like characters of reference indicate corresponding parts in the different figures. 
     
    
     DETAILED DESCRIPTION  
       [0051]    The complete anchoring post system is shown in FIG. 3 and comprises a base member  10  arranged for attachment to a top surface of an elevated support structure such as a transformer where workers are required to carry out various functions and must be protected against the dangers of falling. The base member  10  comprises a base plate  11  with a pair of upstanding lugs  12  which define a support for a pivot pin  13  to which the post  14  can be attached for pivotal movement about a horizontal axis parallel to and spaced upwardly from the plate  11 . The post  14  comprises a base portion  15  which has two lugs  16  extending downwardly therefrom before co-operation with the lugs  12  and receiving the pin  13  the base portion  15  further includes two levelling screws  17  each on a respective side and at 90 degrees from the lugs  16 . The levelling screws  17  are mounted on brackets  18  welded to the side of the base portion  15  and carry a cylindrical sleeve into which is screwed a jack  19  having a base plate  20 . Rotation of the screw jack  19  and the base plate  20  acts to press the base plate against the upper surface of the plate  11  thus levelling the post by rotation about the axis of the pin  13 .  
         [0052]    The post  14  is formed from a plurality of tubular portions each of circular cross section. The tubular portions include the base portion  15 , a bottom tubular portion  21 , a first insert tubular portion  22  and a second insert tubular portion  23 .  
         [0053]    Each of the tubular portions is of slightly less diameter than the next so that each is inserted as a sliding fit into the next. The base portion  15  is fixed to or welded to the bottom tubular portion  21  so that this is fixed and provides a stanchion for the remaining tubular portions  22  and  23 .  
         [0054]    At the top of the uppermost tubular portion  23  is provided a mounting section generally indicated at  24  which includes three rings  25 ,  26  and  27  each of which has respective attachment loop  28  and each of which is mounted for rotation about the vertical axis of the post. Thus each ring has a planar portion mounted on the post in a radial plane of the post with each ring being separated from the next by a slide collar  29  holding the rings at axially spaced positions and allowing each ring to rotate around the post independently of the others. Each attachment loop is carried on the ring and is inclined downwardly and outwardly from the radial plane of the plate portion of the ring to form an attachment to which a suitable tethering hook can be attached for the harness of the worker concerned.  
         [0055]    At the top of the mounting section  24  is provided an open mouth  30  of the top section of the post into which can be inserted an insert piece  31  in the form of a short length of post carrying an additional ring  32  similar to the rings  25 ,  26  and  27 . At the top of the top portion of the post at the mouth  30  is provided an additional ring  33  which also can rotate around the axis of the post and provides an upturned flange  34  having a hole  35 .  
         [0056]    Onto the top section  23  of the post is mounted a jib portion generally indicated at  40  which includes a collar  41  surrounding the top portion  23  with the bottom edge  42  of the collar sitting on an upper edge  22 A of the tubular portion  22 . The collar  41  is formed in two semi-cylindrical portions  41 A and  41 B connected by a hinge  41 C. The hinge  41 C defines a vertical axis along side the upper portion  23  of the post. As shown in FIG. 4, on the opposite side to the hinge  41 C is provided a clamping section  41 D clamping together the to halves  41 A and  41 B. The clamping section includes two screws  43  which are threaded so as to engage into nuts  44  to clamp together the two sections at an abutting edge therebetween. Thus the clamped collar has diameter of its inside surface slightly greater than the outside surface of the upper tubular portion  23  so as to provide a sliding fit thereon allowing rotation of the collar on the tubular portion  23 . A plastics bearing sleeve  45  is provided on the inside surface of the collar to surround the tubular portion  23  to allow ready rotation of the collar on the tubular portion.  
         [0057]    The collar  41  carries a bracket  46  on one side, the bracket being formed by two flanges  46 A and  46 B which project outwardly to this side to carry a pivot pin  47  which has a horizontal pivot axis spaced outwardly from one side of the post. Onto the pin  47  is mounted a jib member  48  of the jib portion. Jib member  48  is formed from two tubular portions  48 A and  48 B which slide one inside the other to a position locked by a transverse pin  48 C. At the outer end of the jib member  48  is provided a pulley mount  49  defined by two parallel flanges  49 A and  49 B supporting between them a pair of pulleys  50  and  51 . The jib member  48  can thus pivot about the pin  47  and is maintained in an upwardly and outwardly inclined orientation by a tether  52  which extends from the end portion  49  to the flange  34  of the ring  33 . As the ring  33  and the collar  41  can both rotate around the post, the jib portion can be moved to any required angular orientation. The lower tubular portion  48 A of the jib member  48  carries a pair of brackets  53  and  54  each for mounting a respective winch for providing a cable for passing over a respective one of the pulleys  50  and  51  to allow the jib portion to act as a lifting mechanism for example for raising and lowering a worker tethered to the post.  
         [0058]    Each of the tube portions  22  and  23  is thus slidable inside its next adjacent partner. Thus the tube portion  22  can slide inside the tube portion  21  and the tube portion  23  can slide inside the tube portion  22 . However the tube portions are guided to limit the amount of axial or longitudinal movement allowed between the portions and also to prevent rotational movement between the two portions. This guiding action is provided by a slot or groove  60  provided in the tubular portion  23  which co-operates with a projectional set screw  61  provided in the tubular portion  22 .  
         [0059]    A symmetrical second groove  63  is provided in the tubular portion  22  which co-operates with a second set screw  64  provided in the tubular portion  21 .  
         [0060]    As best shown in FIG. 5, the set screw  61  has a head  61 A projecting through the inside surface  22 A of the tubular portion  22 . The head  61 A thus extends into the groove  60  sufficiently to ensure that the tubular portion  23  can only move relative to the tubular portion  22  to an extent controlled and guided by the groove  60 .  
         [0061]    When moved to the extended position, the head  61 A is located at the bottom  60 A of the groove  60 . In this position a hole  70  in the tubular portion  23  is aligned with a hole  71  in the tubular portion  22  allowing the passage therethrough of a locking pin  73 . The pin passes through the hole of the tubular portions so as to extend through aligned opposed holes in both of the tubular portions so that ends of the pins project outwardly beyond both sides of the tubular portions. The pin can be locked in place by suitable locking members (not shown). In order to prevent or limit side to side movement of the tubular portion  23  and the tubular portion  22 , a clamping screw  75  is provided mounted in a collar  76  so that a threaded shaft  77  of the screw passes through the wall of the tubular portion  22  and through the inside surface  22 A thereof into engagement with an outside surface  23 A of the tubular portion  23 . Thus the clamping screw operable by a hand wheel  78  presses the tubular portion  23  away from the clamping screw toward the opposite side of the tubular portion  22  to hold in rigidly in place.  
         [0062]    The groove  60  has the lower end thereof  60 A spaced away from the bottom end  23 B of the tubular portion  23 . Also the upper end  60 B of the groove is spaced away from the upper end of the tubular portion  23 . In this way the groove  60  confines the movement of the tubular portion  23  to the required movement between the retracted and extended positions and prevents the tubular portion  23  from moving too far into the tubular portion  22  and also being extracted out of the tubular portion  22 .  
         [0063]    In particular the insertion of the locking pin  73  can be effected readily and quickly simply by pulling the tubular portion  23  up to its full extent defined by the groove  60  whereupon the pin can be readily inserted through the aligned holes  70  and  71 .  
         [0064]    The arrangement of the groove  63  in the portion  22  and its cooperation with a symmetrical set screw  64  and a symmetrical clamping screw  79  operates in exactly symmetrical manner with the exception that the groove  60 , the set screw  64  and the clamping screw  79  are all arranged at 180 degree angular spacing relative to the symmetrical components of the connection between the tubular portion  23  and the tubular portion  22 .  
         [0065]    While the groove  60  is preferred since it avoids weakening the structure, the groove can be replaced by a slot which extends through the wall of the tubular portions  23  and  22 .  
         [0066]    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.