Abstract:
This invention is a lumbar-friendly cargo carrier sled that can be used by humans to move cargo across rough or snow covered terrain and is adapted for use in conjunction with skis or wheels. The sled has an adjustable harness that articulates, by pivoting about three points in two planes. The sled frame itself flexes under dynamic loading conditions to absorb shock, and the harness is adjustable in length to transfer the majority of the load more directly onto the pelvic girdle region via a curved hip plate. The overall result is a lumbar—friendly pack sled that has the capability of maximizing the load that can be transported while minimizing the strain upon the human body.

Description:
BACKGROUND OF THE INVENTION 
   The present invention relates to a cargo carrier that can be utilized by humans, pack animals, ATV&#39;s, snow machines or other motorized terrain crossing equipment to move cargo across rough or snow covered terrain. More particularly, to a lumbar friendly pack sled that is adapted for use in conjunction with skis or wheels, and also having the capability of maximizing the load that can be transported while minimizing the strain upon the human body. 
   Cargo carriers of the dragging style have long been utilized with pack animals, and are most commonly known as “travois”. Although many have been adapted for use with human movers, their use has been relatively minimal. Since these devices generally attach to the upper torso, they are limited in their attachment points and focus primarily on the hips, waist or shoulders. Inevitably, the load must be fully or partially carried by the lumbar region. Since this region is prone to injury the mass of cargo that can be carried is small. 
   Previous personal transportation sled devices lack the ability for articulation about the XY and YZ planes simultaneously so as to compensate for the walking motion of a human. The prior art devices poorly compensate for the shock transmitted from the sled body via the sled&#39;s attachment points onto the human. These drawbacks have prevented the widespread usage of such devices. 
   This new cargo carrier utilizes a hinge pivotable in the XY plane between the sled and the harness, and two pivoting arrangements in the XY and YZ planes. In unison this allows limited articulation between the harness and the sled body. The sled&#39;s main body is built from ski shafts allowing flex under load as well as the ability to compensate for shifting of the center of gravity of the load under dynamic conditions. Its harness adjustment and upper pivot plate design allows for much of the weight to be directly borne by the rear pelvic girdle. Such articulation, shock absorption and weight transfer provide for the option of handling larger cargo masses without placing undue stress on the lower lumbar region of the human body, thus overcoming the abovementioned drawbacks. 
   SUMMARY OF THE INVENTION 
   In accordance with the invention, an object of the present invention is to provide an improved cargo carrier apparatus that can be safely used by humans to transport heavy cargo over rough terrains. 
   It is another object of this invention to provide a cargo carrier sled that has a shock absorption mechanism able to compensate for the shock generated when traversing over rough terrain. 
   It is a further object of this invention to provide a cargo carrier that allows a maximum of upper torso movement without transmitting unnecessary torque or strain onto the human torso. 
   It is still a further object of this invention to provide for a cargo carrier with an articulating harness that allows one to ski while transporting the cargo. 
   It is yet a further object of this invention to provide a cargo carried designed for all season, and all terrain use. 
   The subject matter of the present invention is particularly pointed out and distinctly claimed in the concluding portion of this specification. However, both the organization and method of operation, together with further advantages and objects thereof, may best be understood by reference to the following description taken in connection with accompanying drawings wherein like reference characters refer to like elements. Other objects, features and aspects of the present invention are discussed in greater detail below. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of the first embodiment cargo carrier being used in the ski mode; 
       FIG. 2  is a perspective view of the second embodiment cargo carrier being used in the wheel mode; 
       FIG. 3  is a side perspective view of the first embodiment cargo carrier in the ski mode; 
       FIG. 4  is a top view of the first embodiment cargo carrier in the ski mode; 
       FIG. 5  is a side view of the ski attachment detail; 
       FIG. 6  is a side view of the terrain wheel attachment detail; 
       FIG. 7  is a side view of the second embodiment cargo carrier; 
       FIG. 8  is a top view of the second embodiment cargo carrier; 
       FIG. 9  is a top view of the second embodiment cargo carrier showing the X plane pivot plate; 
       FIG. 10  is a back view of the second embodiment cross carrier showing the Y plane pivot plate; 
       FIG. 11  is a top view of the second embodiment cargo carrier showing the X plane pivot plate tilted to the right; and 
       FIG. 12  is a back view of the second embodiment cross carrier showing the Y plane pivot plate tilted to the left. 
   

   DETAILED DESCRIPTION 
   The cargo carrier sled apparatus of the present invention, comprises a cargo frame, a harness, and a connection plate. The second embodiment, heavy duty sled incorporates upper and lower pivotable plates joined by a connection hinge so as to form an articulating connection between the cargo frame and harness. 
   Referring to FIGS.  1 , 3  and  4 , perspective views of the first embodiment, light duty cargo carrier, the general operation in the ski mode can be seen. Light duty cargo carrier  2  has sled body  3  strapped to human  1  by virtue of harness straps  4  and harness belt  6 . Sled body  3  has two generally parallel rectangular rails  18  of tipless alpine skis. There is nothing remarkable about the skis except that the tips have been removed. The rails  18  exhibit the generally resilient, flexible and spring-like qualities imparted to all modern alpine skis. These are held in relative spacing by upper brace  7  and lower brace  9 . Curved hip cradle  10  partially encircles the hip and waist region. The particular vertical location of cradle  10  is tailored to human  1  by standard adjustment straps located on the back of harness straps  4  (not shown) and the positioning of harness belt  6 . Harness straps  4  are mechanically affixed to upper brace  7 . As the human  1  traverses across a snow covered terrain, light duty cargo carrier  2  moves with him or her, contacting the snow along a bottom surface of ski tip  8 . Adjustment is made as described above so that the weight borne by sled body  3  is transmitted to the top of the hips by hip cradle  10 . This minimizes the load carried by the human&#39;s back, and allows minimal lateral movement of the sled when the human  1  is in motion. 
   Looking at  FIG. 5 , the general arrangement of the attachment of ski tip  8  to sled rails  18  can be seen. Ski tip  8  is mechanically affixed to sled rail  18  by nut and bolt arrangement  22  which is partially nested into recess  24 . Because of the contact ski tip  8  makes with the snow, nut and bolt arrangement  22  is necessarily nested into recess  24  located on the bottom side  26  of the ski tip  8 . This prevents snow or ice entrapment and buildup on the bottom  26  of ski tip  8 . Hinge  28  resides between ski tip  8  and sled rail  18 . This serves to retain ski tip  8  aligned with the longitudinal axis of sled rail  18  while still allowing ski tip  8  to tilt about the axis of hinge pin  34 . 
   Referencing  FIGS. 6 ,  7  and  8 , various views of the second embodiment heavy duty cargo carrier in the wheel mode, the general assembly of the wheel mode can be seen. Here, wheel  12  has been mechanically attached to axle  14  which passes through bearing blocks  16  and is mounted to sled rails  18  by mechanical fasteners  20 . Axle spacer  30  separates the wheels  12 . The diameter of wheel  12  is such that ski tip  8  cannot contact the ground when wheel  12  is installed. This design choice allows for installation of wheels  12  onto heavy duty cargo carrier (sled)  32  without the removal of ski tips  8 . Although bearing block fastener  20  is illustrated as a bolt and nut arrangement, there are numerous other fastening devices that are well known in the art to be the mechanical equivalent, such as circle clips and pins, screws, cross-dowel joiners or rivets to list a few. In a similar fashion, ski tips  8  are mechanically affixed to sled rails  18  by mating engagement between nut and bolt arrangement  22  (As described in detail above). 
   Although, only two wheels  12  are illustrated, the number of wheels  12  can vary in number as determined by the width of the wheel  12  and the size and placement of axle spacers  30 . For lateral stability two wheels  12  and beyond work best. For minimized rolling friction one wheel  12  works best. 
   Note, that the general arrangements for the attachment of ski tips  8  and wheels  12  illustrated in  FIGS. 5 and 6  are common to both the first embodiment  2  and second embodiment  32 . 
   Looking at  FIGS. 2 and 7 , it can be seen that the second embodiment heavy duty cargo carrier  32  has two sled rails  18  spaced substantially parallel by lower cross brace  36  and upper cross brace  38 . Harness  5  has harness straps  4  sandwiched pivotally between hip cradle  10  and upper pivot plate  48 . Harness belt  6  is mechanically affixed to hip cradle  10  as in the light duty embodiment  2 . Heavy duty cargo carrier  32  differs from light duty cargo carrier  2  in its ability to allow the harness straps  4  and belt  6  to pivot in their respective planes thus imparting it&#39;s articulation ability. Optional adjustable hold down straps  40  span between sled rails  18 . 
   Looking at  FIGS. 6 ,  9  and  12  the pivoting capability in the XY plane can best be illustrated. Lower pivot plate  42  is attached to upper cross brace  38  by lower pivot fastener  44  at the approximate mid point of the longitudinal axis of lower pivot plate  42 . Lower pivot fastener  44  extends through a corresponding sized orifice in lower pivot plate  42  and lower cross brace  38 . Optional lower pivot stops  50  are rigidly affixed to lower pivot plate  42  and reside within arced lower pivot slots  52  in lower cross brace  38 . With this arrangement lower pivot plate  42  is free to pivot about first pivot fastener  44  until either of lower pivot stops  50  contact lower pivot slots  52 . This allows limited freedom of movement for harness straps  4 , harness belt  6  and hip cradle  10  in the XY plane without any corresponding movement of the sled rails  18 . Upper pivot plate  48  is mechanically affixed to hip cradle  10  in a similar fashion. 
   Piano hinge  46  is mechanically attached to the edges of lower pivot plate  42  and upper pivot plate  48 . This allows for the harness straps  4 , harness belt  6  and hip cradle  10  to tilt forward or backward without any corresponding movement in sled rails  18 . Conversely, this allows for upward or downward movement of the sled rails  18  without any corresponding movement of the harness straps  4 , harness belt  6  and hip cradle  10 . This eliminates unnecessary rapid changes in load fort the person traversing with the sled  32 . 
   Looking at  FIG. 11  the pivoting design of upper pivot plate  48  and harness strap  4  can best be seen. Upper pivot plate  48  is attached to hip cradle  10  by upper pivot fastener  54  at the approximate mid point of the longitudinal axis of upper pivot plate  48 . Optional upper pivot stops  56  are rigidly affixed to hip cradle  10  and reside within arced upper pivot slots  58  in upper pivot plate  48 . With this arrangement upper pivot plate  48  is free to pivot about upper pivot fastener  54  until either of upper pivot stops  56  contact upper pivot slots  56 . This allows for limited freedom of movement for harness straps  4 , harness belt  6  and hip cradle  10  in the YZ plane without a corresponding movement of the sled rails  18 . 
   An important feature of harness  5  is that the upper pivot plate  48  has a curved bottom edge  60  that transfers the weight on harness  5  onto the pelvic girdle and legs, minimizing the stress on the shoulder and lower lumbar regions. This bottom edge  60  may be optionally padded. 
   When the pivoting and hinging features of cargo carrier  32  are utilized in unison, there is a limited amount of articulation accomplished between the sled  32  and the harness  5 . This allows human  1  to twist or sway his harness laden upper torso, (as would occur when walking or skiing), without transmitting any unbalanced forces to the sled  32 . Effectively, the loading of the sled  32  remains mostly static and unchanged while in transit over terrain, with the mass of cargo being borne by the rear pelvic region and legs. 
   The support for the cargo on either sled may be accomplished using a lightweight removable plate  62  that is mechanically affixed between sled rails  18  so as to form a generally planer surface to support cargo, or by a set of removable resilient straps  41  mechanically affixed between sled rails  18 . Here the light duty sled  2  utilizes straps  41  while the heavy duty sled  32  utilizes the plate  62 . 
   Although only depicted with the light duty sled  2 , hold down straps  40  may be used with either sled and may be belts, webbing, or rope utilizing such fasteners as hook and loop style, snap, clip, tooth and hole or other equivalent devices known in the art. 
   Sled rails  18  and ski tips  8  are fabricated from generally rectangular skis. These thus both allow for flex under load that prevents sudden shock transmission to the user as well as allowing for movement in relation to torsional loads encountered when traversing uneven terrain. 
   Both embodiments also intended for use with ATV&#39;s, snowmobiles and other similar terrain crossing mechanized equipment. For such applications the harness including cradle would be removed and the upper pivot plate would be mechanically affixed to the machine. 
   The above description will enable any person skilled in the art to make and use this invention. It also sets forth the best modes for carrying out this invention. There are numerous variations and modifications thereof that will also remain readily apparent to others skilled in the art, now that the general principles of the present invention have been disclosed.