Patent Publication Number: US-7216386-B2

Title: Carabiner attachment bracket for a basket rescue stretcher

Description:
CROSS REFERENCE TO RELATED APPLICATION 
   This application is a Continuation-in-Part of Ser. No. 10/797,113, now U.S. Pat. No. 6,859,963, filed Mar. 11, 2004 which is a Continuation of Ser. No. 10/361,580, now U.S. Pat. No. 6,725,480 filed Feb. 11, 2003 which claims priority from U.S. Provisional Patent Application No. 60/355,787 filed Feb. 12, 2002, entitled Attachment for a Basket Rescue Stretcher. 

   FIELD OF THE INVENTION 
   This invention relates to an improvement in basket rescue stretchers and in particular to a carabiner attachment for stretchers such as stokes litters. 
   BACKGROUND OF THE INVENTION 
   A basket rescue stretcher of the type utilized by emergency personnel is well known. It generally comprises a sturdy, light-weight, open frame manufactured from stainless steel tubing or like material, comprising both longitudinal and lateral components which are secured by welding or the like, into an integral unit. Common to most rescue stretchers of this type is a sturdy peripheral top rail surrounding the basket stretcher opening, which lends rigidity and strength to the stretcher and also provides a convenient hand-hold for emergency personnel when transporting and injured patient. 
   Conventional basket rescue stretchers are manufactured from stainless steel components, which are welded together. They generally have a sturdy peripheral top rail of 1-inch diameter, which surrounds the basket stretcher opening and one or more intermediate rails of ½ inch diameter material, spaced from and generally parallel to the top rail. Lateral components, or ribs, are secured by welding to the underside of top rail and to the outside of the intermediate rails. The first intermediate rail is generally spaced 2 inches clear of the top rail. 
   The top rail is generally the most convenient attachment point for a tether such as ropes or webbing or the like, which enable emergency personnel to either raise or lower the basket rescue stretcher adjacent to a building or an escarpment. Such tethers are commonly secured to the top rail by screwgate carabiners, which are inserted through a pre-formed loop made in the tether and clipped over the peripheral top rail. The tether may be a so-called litter bridle or sling arrangement which may include four equal length ropes or webbing belts connected to a single lifting ring. 
   Such carabiners are sturdy connection devices, ideally suited to quick connection and release situations. They have a smoothly contoured ‘D’ shape that will only minimally abrade ropes or harnesses. Carabiners may often have corner radii which are smaller than the radius of the tubular top rail. For example a typical top rail may have a radius of ½ to ⅝ of an inch (1 to 1¼ inch diameter) whereas a carabiner may often radius which is significantly smaller. Thus, the difference in top rail and carabiner diameters prevents the carabiner from properly contacting the underside of the top rail of the basket stretcher as tension is applied. In situations where a “shock load” is placed on the basket stretcher, such as if a loaded stretcher was dropped a short distance and then arrested by the carabiners and connecting tethers, opposite sides of the tubular top rail could be crushed slightly, thereby weakening the rail and perhaps rendering the stretcher unsafe for use. 
   When the carabiner is clipped over the peripheral top rail of a basket rescue stretcher and tension applied to the connecting tethers, the carabiner will slide along the top rail unless the direction of the tension is close to a right angle with the top rail, or movement of the carabiner is arrested by contact with one of the lateral frame components secured to the top rail. Such movement of the connecting point between tether and stretcher in undesirable since it results in an imbalance of both stretcher and patient and could further endanger the patient. 
   Further, as tension is applied to the tether straps during suspension of the basket stretcher, the top rail of the basket stretcher prohibits the carabiner from rotating so as to lie in the plane of the tether straps or webbing were the webbing to remain flat, resulting in the carabiner being misaligned generally 90 degrees from such an orientation causing a helical twist in the straps or webbing. 
   Clipping the carabiner over the top rail of the basket stretcher places a portion of the carabiner in an exposed position outside the periphery of the stretcher. Such an outwardly exposed portion may snag on surface irregularities on the adjacent surface of a building or an escarpment as the basket stretcher is raised or lowered resulting in tipping and jerking of the basket stretcher as it elevates or descends. Further, such contact may result in rapid abrading and deterioration of the carabiner. 
   SUMMARY OF THE INVENTION 
   The stretcher of the present invention has attachment brackets which are inwardly disposed into the stretcher basket and located near the fore and aft ends of the stretcher, located equidistant from a longitudinal axis of the stretcher. Brackets which extend externally of the stretcher may also be employed, and if so, advantageously they form a smoothly curved surface to avoid snagging. The brackets permit the stretcher to be raised or lowered adjacent to a vertical or inclined surface, such as the outside of a building or an escarpment, in a manner which is relatively balanced and stable and which reduces snagging or abrading of lifting equipment against the adjacent surface of the slope. 
   The attachment brackets according to the present invention may be, as an example, manufactured from ½ inch diameter stainless steel rod. The brackets may form a generally inverted “L” shape, having first and second legs. The first leg may be substantially shorter than the second. The internal corner radius between the legs may be, for example, ½ inch, so as to match the corner radius on most standard carabiners. The attachment brackets may be secured by welding, or other rigid fastening, to the inside of the basket stretcher so as to extend between the peripheral top rail and, for example, the immediately adjacent second rail. 
   The first leg of the attachment bracket may be mounted to the inside face of the top rail so as to extend inwardly of the bracket and radially downwardly from the top rail. The second leg of the bracket may extend downwardly and may be angled toward the outside of the basket stretcher so as to intersect in a rigid mounting to the upper surface of the immediately adjacent lower rail. The attachment may also be a flat plate having an aperture to receive the carabiner therethrough. 
   The mounting member according to one aspect of the present invention is for mounting to at least an upper rail of a basket rescue stretcher, for example so as to provide for clipping of a carabiner to or adjacent the upper rail. The mounting member is adapted for mounting, at at least one end of the mounting member, to an inner side of the rail so as to project the mounting member into the interior of the stretcher, as defined by the top rail of the stretcher. In one embodiment the mounting member is for mounting, at an oppositely disposed end, to a longitudinal member of said basket rescue stretcher extending longitudinally along the basket. The mounting member may be provided for retrofit to existing basket rescue stretchers or may be formed as part of, or mounted to as part of the manufacture of new basket rescue stretchers. 
   The mounting member is rigid and may be a bracket, or loop, or apertured plate which is mountable or mounted to the stretcher so that when a clip, carabiner, hook or the like is attached to the mounting member, twisting of the sling webbing is avoided. 
   In a further aspect, the present invention may be characterized as a basket rescue stretcher apparatus or system which includes a pair of top rails extending longitudinally along upper opposite side edges of the stretcher, so as to define an opening into a stretcher cavity within the stretcher, and a pair of carabiner mounting members rigidly mounted or mountable to or adjacent each top rail. The carabiner mounting members are mounted or mountable spaced longitudinally apart relative to each top rail. Carabiner mounting members extend at least into the stretcher cavity and each define a carabiner receiving opening which lies in a first plane which is perpendicular to a vertical second plane containing the corresponding top rail to which the carabiner mounting member is mounted or mountable which is inclined relative and to a horizontal third plane which contains the pair of top rails so that the mounting member is substantially co-planar with the corresponding tether strap when the stretcher is lifted by the tether straps. Carabiner mounting members may also protrude outwardly from a circumference of the stretcher defined by the pair of top rails. Advantageously, when a carabiner is mounted through the carabiner receiving opening, it passes through the opening of a mounting member, that is, that portion of the carabiner which passes through the opening is aligned substantially parallel to the corresponding top rail adjacent the carabiner mounting member. 
   In one embodiment the stretcher further includes a pair of side rails extending longitudinally along opposite sides of the stretcher between the pair of top rails and a floor of the stretcher. In such an embodiment the carabiner mounting members may also be rigidly mounted to the pair of side rails. In such an embodiment the pair of side rails may be substantially parallel to the pair of top rails, and each carabiner mounting member may be an elongate member having an upper end mounted to a corresponding top rail and a lower end mounted to a corresponding side rail. 
   In one embodiment of the present invention the elongate member may be a bar having an inverted L-shape so as to form the carabiner receiving opening as an upper elbow of the bar protruding inwardly of the corresponding top rail and side rail. In another embodiment, the elongate member may be a plate having an aperture, for example in its upper end, so that the aperture forms the carabiner receiving opening. In such embodiments, the plate and bar have a thickness which is not larger than the size of the opening in an elbow in a carabiner to which the carabiner mounting member would be mounted. In embodiments having mounting members extending externally of the stretcher cavity, the members preferably have smoothly curved outermost surfaces for example that blend smoothly with the curvature of the outer circumference of the top rails so as to minimize snagging of the mounting members as the stretcher is raised against buildings, etc. Whether the mounting members are internal or external to the stretcher cavity, they may be advantageously inclined from the vertical so as to align with the tether straps once tensioned during a lifting of the stretcher. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1 , is a plan view of a typical basket stretcher incorporating lifting brackets according to the present invention. 
       FIG. 1   a  is a perspective view of a portion of a conventional basket rescue stretcher and lifting harness. 
       FIG. 1   b  is a sectional view along line  1   b — 1   b  in  FIG. 1   a.    
       FIG. 2  is a perspective side view of the basket stretcher of  FIG. 1 . 
       FIG. 3  is an enlarged perspective view of a portion of  FIG. 1 , illustrating a lifting carabiner and strap clipped to a lifting bracket. 
       FIG. 3   a  is an alternative embodiment of the lifting bracket of  FIG. 3 . 
       FIG. 3   b  is, in perspective view, a further alternative embodiment of the lifting attachment bracket according to the present invention. 
       FIG. 3   c  is a sectional view along line  3   c — 3   c  in  FIG. 3   b.    
       FIG. 3   d  is in sectional view laterally through the stretcher rails, a further alternative embodiment of the lifting attachment bracket according to the present invention. 
       FIG. 4  is a further enlarged, partially cut away perspective view taken from  FIG. 3 . 
       FIG. 5  is a sectional view along line  5 — 5  in  FIG. 3 . 
       FIG. 6  is a sectional view along line  6 — 6  in  FIG. 3 . 
       FIG. 7  is, in side elevation view, a further alternative embodiment of the lifting attachment brackets mounted to a stretcher according to the present invention. 
       FIG. 8  is a partially cutaway enlarged perspective view of the stretcher of  FIG. 7 . 
   

   DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION 
   With reference to the drawing figures wherein similar characters of reference denote corresponding parts in each view, as seen in  FIGS. 1 and 2  basket rescue stretcher  10  includes longitudinal and lateral members such as stringers  12  and ribs  14 . Stringers  12  and ribs  14  are welded together to form a rigid elongate low-sided basket. Continuous peripheral top rail  12   a  surrounds the basket opening. One or more intermediate rails  12   b  are spaced from and parallel to top rail  12   a.    
   In the prior art as seen in  FIGS. 1   a  and  1   b , a conventional lifting tether  16  is attached to the top rail  12   a  of basket stretcher  10  by conventional screwgate carabiners  18 . When lifting tether  16  is tensioned in direction A, carabiner  18  will have a tendency to slide longitudinally along top rail  12   a  unless carabiner  18  is positioned such that any sliding movement that occurs will be immediately arrested by contact with a lateral frame component  14 , such as a rib, which intersects and is secured to the top rail. Such contact between carabiner  18  and rib  14  may not be properly balanced for lifting of stretcher  10 . 
   Top rail  12   a  may typically have a diameter in cross section which is larger than the size of the opening of corner  18   a , that is, has a radius r which is significantly larger than the internal corner radius r′ of corner  18   a  of carabiner  18 . This difference in radii prevents the proper nesting of the underside of top rail  12   a  into snug mating with the corner radius of corner  18   a  of carabiner  18 , thereby leaving a gap B. If a loaded stretcher is dropped a short distance and then arrested by carabiners  18  and connecting tethers  16 , the sides of the tubular top rail  12   a  may be crushed slightly, or otherwise weakened by the pinching of the top rail in the radius of corner  18   a.    
   Further, as seen in  FIG. 1   a , top rail  12   a  may prohibit the carabiner  18  from rotating into planar alignment with tether straps  16   a  were they to remain untwisted, resulting in the tether straps  16   a  being helically twisted for example through 90 degrees between the carabiner and the tether strap gathering ring  16   b.    
   As also seen in  FIGS. 1   a  and  1   b , a substantial portion of carabiner  18  protrudes outwardly of top rail  12   a  and thus may be prone to snagging an adjacent surface of a building or an escarpment over which the stretcher is being translated. Such contact may result in tipping or jerking of the basket stretcher as, for example, it is elevated or lowered. Such contact may also result in rapid deterioration of the carabiner. 
   As better seen in  FIGS. 3–6 , carabiner mounting or attachment brackets  20  are rigidly mounted to top rail  12   a  and to an adjacent member such as intermediate rail  12   b . Brackets  20  extend inwardly of the basket of stretcher  10 , that is, towards the centerline of the stretcher. They may be manufactured for example from ½ inch diameter stainless steel rod. Brackets  20  have, in one embodiment which is not intended to be limiting, first and second legs  20   a  and  20   b  respectively, extending from an intermediate arcuate corner or shoulder  20   c . Advantageously corner or shoulder  20   c  has a corner radius that matches, that is corresponds to, or exceeds the corner radii of corners  18   a  of standard carabiners, and has a smaller cross sectional diameter than the size of the corner opening of a standard carabiner so as to avoid the pinching problem. First leg  20   a  may be substantially shorter than the second leg  20   b , so that bracket  20  takes the form of an inverted “L”. In the alternative embodiments shown in  FIG. 3   a , which again is not intended to be limiting, attachment brackets  20 ′ and  20 ″ are formed as a rigid elongate plate mounted at their ends to rail  12   a  and  12   b . Each plate has an aperture ( 20   a ′) for receiving a carabiner hooked therethrough and is sufficiently thin so as to snugly nest into corner  18   a  of the carabiner without pinching. In  FIGS. 3   b  and  3   c , attachment brackets  20 ″ are mounted to fore and aft ribs  14  so as to extend along the length of the ribs between rails  12   a  and  12   b.    
   Brackets  20 ,  20 ′ and  20 ″ are mounted on the inside of stretcher  10  with, for example, first leg  20   a  or the plate secured, as by welding, to the inwardly exposed face of top rail  12   a . Brackets  20 ,  20 ′ and  20 ″ extend inwardly of the basket from top rail  12   a  and downwardly until their lower end, for example the lower end of second leg  20   b , contacts the upper surface of the immediately adjacent lower rail  12   b , where it is mounted by welding or the like. 
   Brackets  20 ,  20 ′ and  20 ″ may be positioned singularly or in pairs on the inner sides of stretcher  10 , adjacent each end. The positioning may advantageously be equidistant from the center of mass of stretcher  10 , so as to provide stable and balanced attachment points for lifting or lowering the stretcher and an associated patient. 
   The attachment brackets may be shaped, for example, other than in the form of an inverted “L”. For example a hook or loop or eye or linear or arcuate strut or member extending between the top rail and an adjacent intermediate rail or a stringer, on the inside of the basket of the stretcher, will serve as a clipping mount for a carabiner  18  if the carabiner is, when clipped on and under tension, lying in a plane which is generally parallel to the top rail and the carabiner is solely under tension with no bending moment acting to bend the carabiner out of its planar shape, and preferably free to rotate about its radii  18   a  without a pinching applied to the top rail. 
   Thus, in one embodiment not intended to be limiting, the attachment brackets may be characterized as not protruding outwardly of the circumference of the stretcher defined by the top rails, but rather, as protruding only inwardly from the top rails along first planes D as shown in  FIGS. 1 ,  3 , and  6 . First planes D are perpendicular to vertical second planes E. Vertical second planes E are aligned such that they contain one of top rails  12   a  such as seen in  FIGS. 3 and 6 . The carabiner receiving openings, such as defined by corner  20   c  or by aperture  20   a ′, may be characterized as lying the first planes D. First planes D may also be characterized as being orthogonal to a third plane F which contains the pair of top rails  12   a  on opposite sides of the stretcher. In other embodiments, such as seen in  FIG. 3   d , stretcher  10  may include attachment brackets  20 ″ that protrude inwardly of top rails  12   a  and attachment brackets  20 ′″ that protrude outwardly of top rails  12   a . Outwardly protruding attachment bracket  20 ′″ is advantageously smoothly contoured so as to minimize the prospects of it catching or snagging against for example, the side of a cliff as the stretcher is raised up a cliff. 
   In yet a further embodiment as seen by way of example in  FIGS. 7 and 8 , attachment brackets  20 ″ may be inclined so as to be substantially co-planar (eg., first plane D) with tether straps  16   a  when tensioned during lifting of the stretcher. This arrangement minimizes the shear force exerted laterally on the brackets and welds relative to the long axis of the brackets, the force on the brackets being then substantially in tension along the bracket. 
   As will be apparent to those skilled in the art in the light of the foregoing disclosure, many alterations and modifications are possible in the practice of this invention without departing from the spirit or scope thereof. Accordingly, the scope of the invention is to be construed in accordance with the substance defined by the following claims.