Abstract:
Top rails of a ladder, where the top rails include a left and right top rail, each attachable to or forming part of the left and right hand rails respectively of the ladder. The two top rails are designed to diverge, creating room for a climber to easily pass between the two top rails. Each top rail is attachable to either a scaffold horizontal or vertical member through an attachment member positioned at or near the end of each top rail.

Description:
FIELD OF INVENTION  
         [0001]    This invention relates to scaffold structures and, in particular, to top rails for scaffold ladders.  
         BACKGROUND OF THE INVENTION  
         [0002]    Devices for accessing or mounting a scaffold platform generally consist of ladders, either added on to the structure of the scaffold structure or climbing the structure of the scaffold itself. It is difficult for a climber to easily and safely exit the ladder onto a scaffold deck, as the ladders typically require the climber to swing around the ladder at the point of exit.  
         OBJECTS OF THE INVENTION  
         [0003]    It is an object of the invention to provide top rails for a scaffold ladder that allows a climber to easily and safely exit the ladder.  
           [0004]    It is an object of the invention to provide top rails for a scaffold ladder that can be easily attached to existing ladders.  
         SUMMARY OF THE INVENTION  
         [0005]    The invention is top rails of a scaffold ladder, where the top rails are a left and right top rail, each attachable to or forming part of the left and right hand rails respectively of the ladder. The two top rails are designed to diverge, creating room for a climber to easily pass between the two top rails. Each top rail is attachable to either a scaffold horizontal or vertical member through an attachment member positioned at or near the end of each top rail. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]    [0006]FIG. 1 depicts a side view of a scaffold structure with a scaffold ladder having the top rails attached.  
         [0007]    [0007]FIG. 2A is a detailed front view of one embodiment of a top rail.  
         [0008]    [0008]FIG. 2B is detailed side view of one embodiment of a top rail.  
         [0009]    [0009]FIG. 3 is a prospective of a top rail showing an alternative attachment member. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0010]    The invention is top rails for scaffold ladders. Shown in FIG. 1 is a scaffold structure  100 , having horizontal  101  and vertical members  102  (collectively, scaffold members). Shown on the vertical members are rings or cups  103 , designed as attachment points for the horizontal and vertical members. Also shown is a scaffold platform  105 .  
         [0011]    Connected to the scaffold structure  100  is a scaffold ladder  10 , having right  11  and left  12  hand rails, and a series of rungs  12  disposed between the hand rails. The top section of the ladder above the platform  105  has a right top rail  1  and a left top rail  2 . As shown, the right top rail  1  is a continuation of the right hand rail  11 , and the left top rail  2  is a continuation of the left hand rail  12 . The left and right top rails  1  and  2 , instead of being parallel, diverge in the plane of the ladder rails  11 ,  12  above the scaffold platform. The top rails  1  and  2  are designed to provide the climber with hand holds as the climber ascends the ladder until the climber&#39;s feet are at or near the scaffold deck, while the divergence for the top rails  1  and  2  allow the climber to easily pass between the top rails  1  and  2  to gain entry to the scaffold deck  105 . Without the divergence, a climber would be forced to swing around the ladder  11  to gain access to the scaffold platform  105 , an obviously dangerous maneuver. As shown in FIG. 2A, each top rail diverges, or has an outward bend, providing an additional 1 foot 1 inch of clearance.  
         [0012]    Shown in FIG. 2A is a detailed view of one embodiment of a right top rail  1  (a left top rail  2  would, in essence, be a mirror image of a right top rail). The top rail  1  is a pipe having two bent sections. The bottom of the top rail  1  has a flared end  20  for fitting over and attaching to the top of a ladder hand rail, in a male-female interlocking relationship. Obviously, the ladder itself could be made with the top rail incorporated into the hand rail. Other means of joining the top rail to the ladder are available (bolts, brackets, etc).  
         [0013]    As shown, the top rail  1  is a pipe section, having two bends, A and B. Obviously, the top rail could be constructed in two or more pieces or sections to accommodate this geometry. Bend A is positioned about 5 inches from the flared end  20  or join with the ladder and is in the plane of the ladder hand rails  11  and  12 . The Bend produces the divergence in the right  1  and left top rails  2  away from the ladder hand rails. Bend B (see FIG. 2B) is located at the top of the top rails  1  and  2 , and is 90 degrees from the plane of bend A. The purpose of Bend B is to position the top rail  1  for attachment to the scaffold structure  100  through attachment member  30 . The scaffold ladder  11  is generally offset from the scaffold structure  100  due to the clamping of the ladder to the structure (one type of clamp is shown in U.S. Pat. No. 6,044,930, incorporated by reference). Since the scaffold ladder  11  is attached to the scaffold structure  100  in a vertical orientation and generally offset from the scaffold structure, the top rails  1  and  2 , being a continuation of the hand rails  11  and  12 , will require a top section which is offset at 90 degrees to properly position the attachment member  30  for attachment to the scaffold structure  100 . For a scaffold ladder attached to the scaffold by the clamp shown in U.S. Pat. No. 6,044,930, a 90 offset of about 9.75 inches is suitable.  
         [0014]    Also shown is attachment member  30 , for attaching the top rail  1  or  2  to the scaffold structure  100 . The embodiment shown is a hook section with a pivotal latch (not shown) for grasping the cups  103  located on the vertical scaffold members  102 . A detailed description of this particular latch is contained in U.S. Pat. Nos. 5,078,532 and 5,028,164 issued to Williams, hereby incorporated by reference. Other types of attachment members  30  could be used. For instance, simply a hooked section for attachment to a scaffold horizontal member  101 , or a clamp attachable to either a horizontal or vertical scaffold member (a clamp attachable to a vertical member is shown in FIG. 3), a hook section attachable or engagable to an annular ring or cup positioned on the vertical scaffold member, or alternatively, attached by U-bolts around a vertical or horizontal scaffold member though a plate or flange positioned on the top of the top rail, etc.  
         [0015]    Finally, as shown in FIG. 1, is gate  50 , attached to the scaffold structure  100  and positioned to open between the top rails. Gate  50  with opens inward toward the scaffold interior and is present to block the opening between the top rails as a safety measure.  
         [0016]    Although the present invention has been described in terms of specific embodiments, it is anticipated that alterations and modifications thereof will no doubt become apparent to those skilled in the art which are intended to be included within the scope of the following claims.