Abstract:
The present invention provides a new material handling cart adapted for easy travel over uneven surfaces including a pair of independently extendable handles, and optionally having a convertible secondary deck assembly.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates material handling carts and more particularly to a new material handling cart adapted for use on and off of flat surfaces. 
   2. Description of the Prior Art 
   Material handling carts are well known in the prior art. Hardware and large home-improvement department stores often supply carts for use by their customers for carrying construction or home-improvement supplies, such as lumber. These carts generally consist of a pair of upright side rails supported on a horizontal deck, which in turn is carried by a plurality of wheels or casters. 
   While these known carts provide a means for transporting supplies, the known carts have several drawbacks. The known carts are provided with small diameter wheels or casters that, while providing relatively easy movement over hard, flat surfaces such as concrete floors and asphalt parking lots, are difficult or impossible to use in “off-road” conditions such as at construction sites or through loose gravel. The known carts are also equipped with stationary handles, which become difficult to reach when trying to move large and/or long materials and make maneuvering of the cart difficult around corners, such as at fence gates and doorways. 
   The known carts are also limited in the variety of materials that may be handled at one time. If a product to be moved is odd-shaped, then it becomes difficult to stack additional supplies on the cart for simultaneous transport. Thus, the customer or handler must make multiple trips to securely transport the different materials. 
   In these respects, there is a need for a material handling cart that is well adapted for travel over uneven ground and irregular surfaces, such as grass, dirt and gravel; which includes easily reachable handles; and further including a means for safely carrying multiple, different-shaped materials. 
   SUMMARY OF THE INVENTION 
   In view of the foregoing disadvantages inherent in the known material handling carts, the present invention provides a new material handling cart adapted for easy travel over uneven surfaces including a pair of independently extendable handles, and optionally having a convertible secondary deck assembly. 
   The material handling cart of the present invention generally comprises a primary deck supported on at least two, spaced apart, rotatable wheel assemblies. The cart further includes a first side-rail assembly connected to the primary deck at a first side and a second side-rail assembly connected to the primary deck at an opposing second side, each of which are adapted and positioned to prevent the lateral movement of objects transported by the material handling cart. Each of said first and second side-rail assemblies include an independently extendable handle assembly comprising a handle tube connected to the respective side-rail. The handle tube preferably has a longitudinal axis substantially perpendicular to the axis of rotation of the rotatable wheel assemblies. The handle tube includes an inner passage and an inner handle member adapted to be received and seated concentrically within the inner passage and further adapted to be selectively positioned therein. The inner handle member is preferably longer than the handle tube and adapted to be slidably seated within the inner passage of the handle tube. The inner handle member is further adapted to be adjustably positioned such that the inner handle member may extend outwardly from the handle tube. Preferably, each independently extendable handle assembly further includes a means for securing the inner handle member at a desired outwardly extending position. 
   Optionally, the cart may include a convertible secondary deck assembly. Preferably, the secondary deck assembly comprises a first convertible deck arm and second convertible deck arm. The first convertible deck arm includes a first end and a second end, the first end being pivotably connected to one of the first and second side-rails at a position vertically spaced from the primary deck and more preferably pivotably connected to a handle tube at a position vertically spaced from a first end of the primary deck. The first convertible deck arm is adapted to pivot about an axis substantially parallel to the longitudinal axis of the respective side-rail to which it is pivotably connected. The second end is adapted to make rotation-limiting engagement with the opposite side-rail at a position vertically spaced from the primary deck and preferably at a position vertically spaced from a first end of the primary deck. 
   The second convertible deck arm includes a third end and a fourth end, the third end being pivotably connected to one of the first and second side-rails at a position vertically spaced from the primary deck, more preferably pivotably connected to a handle tube at a position vertically spaced from the second end of the primary deck, and horizontally spaced from the first convertible deck arm. The second convertible deck arm is adapted to pivot about an axis substantially parallel to the longitudinal axis of the side-rails. The fourth end is adapted to make rotation-limiting engagement with the opposite side-rail to the side-rail which the third end is pivotably connected, preferably at a position vertically spaced from the second end of the primary deck and horizontally spaced from the first convertible deck arm. The first and second convertible deck arms may be pivotably connected to the same or different side-rails. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a material handling cart of the present invention. 
       FIG. 2  is a side view of a material handling cart depicted in  FIG. 1 . 
       FIG. 3  is a top plan view of a material handling cart shown in  FIG. 1  having the first and second side-rails removed. 
       FIG. 4  is an rear end view of the material handling cart illustrated in  FIG. 1 . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   A presently preferred embodiment of the invention is described below with reference to the drawings, in which like reference numerals refer to like elements in the various views. Referring to the drawings and particularly to  FIGS. 1 and 4 , there is illustrated a material handling cart, generally designated  10  having a first side  11 , a front end  13 , a rear end  15  and a second side  17 . Generally, the material handling cart  10  includes a primary deck  12  including a floor panel  14  of a suitable material such as aluminum, plastic or other sheet material. Preferably, and as shown, the primary deck  12  and floor panel  14  are substantially rectangular. The dimensions may be any that are desired, but preferably, the width (distance between the first and second sides  11  and  17 ) is selected such that the material handling cart may be navigated through standard doorways and gate openings. Preferably, the primary deck includes support beams  16   a–f  (shown in phantom in  FIG. 3 ) about the perimeter and across its lower width by support beams  16   g  and  16   h  to support the floor panel  14  and thereby reinforce the load carrying capacity of the deck  12 . 
   The material handling cart  10  further includes at least two spaced apart wheel assemblies  20 . The wheel assemblies  20  each include wheel support brackets  18  that are positioned at opposing sides of the primary deck  12  and are adapted to receive and support a wheel  21 . Preferably, the wheel assemblies are positioned centrally to the length of the primary deck  12  such that loads are easily centered and balanced for transport. The wheel assemblies  20  preferably include a rubber tire  21   a  having a sufficient diameter to allow the material handling cart  10  to be navigated over rough terrain, such as gravel, and that easily passes over uneven surfaces. 
   The material handling cart  10  further includes a first side-rail assembly  22  and a second side-rail  24 . The first and second side-rails  22  and  24  are connected to the primary deck  12  at opposing sides and preferably have longitudinal axis parallel to the rotation axis of the wheels  21 . The first and second side-rails  22  and  24  are preferably made of a suitable material such as aluminum pipe, although other materials such as wood and plastic may be used. Any configuration of the side-rails is suitable so long as the side-rails provide for the lateral containment of objects being transported by the material handling cart  10 . The first and second side-rails  22  and  24  are shown in a substantially inverted U-shape configuration; however, such a shape is merely a preference and other shapes are readily envisioned. Preferably, as shown in  FIGS. 1–2 , the first and second side-rails  22  and  24  each comprise a substantially continuous metal pipe having a front leg  28 , a front corner  29 , a top rail  30 , a rear corner  31  and a rear leg  32 . Optionally, the side-rails may be fitted with a mesh, screen or sheet wall (none shown) so that small items that otherwise might pass laterally through the space between the front leg  28 , rear leg  32 , primary deck  12  and top rail  30  are contained. Likewise, a suitable mesh, screen or wall may be fitted between the front leg  28  of the first side-rail  22  and the front leg  28  of the second side-rail, or between the rear legs  32  for similar function. 
   The first and second side-rails  22  and  24  are preferably removably connected to the primary deck  12 . This is accomplished by providing a plurality of support sleeves  26  that are rigidly connected to the primary deck  12 . Each of the plurality of support sleeves  26  include a cavity  26   a  (seen in  FIG. 3 ) having an inner diameter greater than the outer diameter of the pipe or other material from which the side-rails  22  and  24  are fashioned. The plurality of support sleeves  26  are appropriately spaced and each are adapted to receive a leg of the side-rails  22  and  24 . As best illustrated in  FIG. 2 , the support sleeves  26  each preferably include a shoe member  27  that closes the bottom of the support sleeve  26 . When the legs  28  and  32  of the side-rails  22  and  24  are inserted into the support sleeves, the bottoms of the front and rear legs  28  and  32  rest in the support sleeves  26  on the shoe members  27 . A retaining pin  33  may be provided that can be inserted through complimentary apertures in the support sleeves  26  and respective legs  28  and  32  to prevent the unwanted removal of the side-rails  22  and  24 . The shoe members  27  are preferably inclined such that when the material handling cart is allowed to rest upon a surface, the underside of the shoe member  27  engages the surface over substantially its entire lower surface area. In other words, the inclination of the shoe members  27  provide for increased contact with the surface and thereby reduces the risk of slipping or rolling, especially when the cart is brought to rest on an incline, since the underside of the shoe members  27  rest flat on the surface. Optionally, each of the shoe members  27  may be fitted with a rubber sole to increase the friction with the support surface and/or to prevent scratching of flooring surfaces. 
   Each of the first and second side-rail assemblies  22  and  24  include an independently extendable handle assembly  40 , which is best illustrated in  FIG. 2 . For ease of illustration, the description of the independently extendable handle assembly  40  will be made with respect to the first side-rail assembly  22 ; however, such description is equally applicable to the independently extendable handle assembly  40  of the second side-rail assembly  24 . The independently extendable handle assembly  40  comprises a handle tube  41  connected to the first side-rail  22  and preferably includes a longitudinal axis substantially perpendicular to the axis of rotation of the rotatable wheel assemblies  20 . Preferably, the handle tube  41  extends parallel to the primary deck  12  and the full length of the first side-rail  22 . Preferably, the handle tube  41  includes a first portion  41   a  and second portion  41   b  that extend outwardly beyond the front leg  28  and rear leg  32  respectively for reasons that will become more apparent below. The handle tube  41  includes an inner passage  42  (shown in phantom lines in  FIG. 2 ) extending substantially the length thereof and adapted to receive a inner handle member  43 . The inner handle member  43  comprises a rod or tube having an outer diameter less than the inner diameter of the handle tube  41  such that the inner handle member  43  may be slidably received by the handle tube  41 . The inner handle member  43  is preferably longer than the handle tube  41  and is further adapted to be adjustably positioned such that the inner handle member  43  may extend outwardly form the handle tube  41  a desirable amount. A rear stop  45   a  may be provided on the handle tube  41  to prevent the inner handle member  43  from extending beyond the rear end of the handle assembly  40 . Preferably, the independently extendable handle assembly  40  further includes a means for adjustably securing the inner handle member  43  at desired outwardly extending positions, such as a hand-turnable setscrew  44  extending through a front stop collar  45   b . Alternatively, the inner handle member  43  could be provided with a plurality of longitudinally spaced apertures that could be independently aligned with a complimentary aperture provided through the stop collar  45 . In such a case, a pin could then be placed through the aligned apertures to secure the inner handle member  43  in a selected position. 
   In another embodiment of the invention (not illustrated), the handle tube  41  is open at both ends and both the front and rear ends include a means for securing the inner handle member  43 . The inner handle member  43  may then be selectively extended from either end of the cart  10 . Thus, one inner handle member  43  could be extended and secured outwardly from the front end  13 , while the other inner handle member  43  is extended outwardly and secured at the rear end  15 . This feature doubles the usable length of the cart  10  by allowing one operator to push on an inner handle member while a second operator pulls on the opposite inner handle member. 
   Optionally, the material handling cart  10  further includes a convertible secondary deck assembly, shown generally at  60 . The secondary deck assembly  60  comprises a first convertible deck arm  61  and second convertible deck arm  62 . The first convertible deck arm  61  preferably is comprised of similar material to the side-rails and includes a first end  63  and a second end  64 . As best shown in  FIG. 1 , the first end  63  is pivotably connected to the first side-rail assembly  22  at a position vertically spaced from the primary deck  12 , and more preferably pivotably connected to the first portion  41   a  of the handle tube  41  at a position vertically spaced from the front end  13  of the primary deck  12 . However, the first convertible deck arm  61  may also be connected to the top rail  30  or any other position on a side-rail. In  FIGS. 1 and 2 , the first end  63  includes a deck arm sleeve  66  that is adapted to fit over and around the handle tube  41  at the first projection  41   a . In other words, the deck arm sleeve  66  includes a passage having an inner diameter greater than the outer diameter of the handle tube  41 . The first convertible deck arm  61  is retained on the handle tube  41  by stop collar  45   a . Thus, the deck arm  61  can rotate freely about the handle tube  41 . As the skilled artisan will appreciate, the first convertible deck arm  61  may be pivotably attached to either the first side-rail  22  or the second side-rail  24 . The second end  64  is adapted to make rotation-limiting engagement with the second side-rail  24 . Preferably, the second end  64  includes an engagement bracket  65  that enables the first convertible deck arm  61  to rest on the opposing side-rail in a substantially horizontal position. The engagement bracket  65  may take any form, such as an L-bracket as shown in  FIG. 4  or a semi-circular bracket having a central axis parallel to the handle tube, as shown in  FIG. 1 . The engagement bracket  65  ensures that the first convertible deck arm  61  has a length greater than the distance between the first and second side rails  22  and  24 . Thus, the deck arm  61  may pivot about the first end  63  until the second end  64  engages the opposing side rail and may rest thereupon. 
   The second convertible deck arm  62  is preferably comprised of similar material as the side-rails and includes a first end  63  and a second end  64  identical to that described for the first convertible deck arm  61 . As best shown in  FIGS. 1 and 2 , the first end  63  is pivotably connected to the first side-rail assembly  22  at a position vertically spaced from the primary deck  12 , and more preferably pivotably connected to the second portion  41   b  of the handle tube  41  at a position vertically spaced from the rear end  17  of the primary deck  12 . However, the first convertible deck arm  61  may also be connected to the top rail  30  or any other position on a side-rail. In  FIGS. 1 and 2 , the first end  63  includes a deck arm sleeve  66  that is adapted to fit over and around the handle tube  41  at the second portion  41   b  and is retained on the handle tube by the rear stop  45   a.    
   The first and second deck arms  61  and  62  may also be connected together by a cross arm (not illustrated) that would provide for the simultaneous pivoting of both arms. Thus, an operator may engage the convertible secondary deck assembly by manipulating only the closest deck arm. A plurality of such cross arms or mech screen may be provided to create a basket-like secondary deck. When not engaged by and resting upon the opposing side rail, the first and second convertible deck arms  61  and  62  hang parallel to the front and rear legs  28  and  32 . Optionally, the front and rear legs  28  and  32  may include a retaining element (not shown) to prevent the arms  61  and  62  from swinging freely when not in use. 
   While various features of the invention have been particularly shown and described in connection with the illustrated embodiments of the invention, it must be understood that these particular arrangements merely illustrate, and that the invention is to be given its fullest interpretation within the terms of the appended claims.