Abstract:
A foldable and portable pallet jack for transporting pallets comprises width-adjustable and folding forks. The skid forks adjust to different sized pallets or materials. The skid forks also fold upright against the handle section of the pallet jack allowing it to be compactly transported and stored. With the forks in a horizontal and locked position, the pallet jack provides normal lifting and transporting of heavy pallets or material in a conventional manner.

Description:
RELATED APPLICATIONS 
     The present invention was first described in U.S. Patent Provisional No. 61/592,899 filed on Jan. 31, 2012 the entire disclosures of which are incorporated herein by reference. 
     FIELD OF THE INVENTION 
     The presently disclosed subject matter is directed toward pallet jacks. More particularly the present invention relates to a foldable and portable pallet jack having skid forks that width adjust to fit different sized pallets or materials. 
     BACKGROUND OF THE INVENTION 
     Most every consumer products, food products, raw materials, or other packaged goods at one (1) time or another are transported on a shipping pallet. The ubiquitous shipping pallet provides an easy, low cost, and very flexible means to move packaged goods, heavy equipment and large groupings of materials quickly and efficiently. 
     Because of their myriad uses and efficiency shipping pallets can be moved by lift trucks, tow motors, and specialized pallet conveyances. However, in stores, smaller warehouse spaces, and other relatively confined areas shipping pallets are usually moved by a pallet jack. 
     A pallet jack is a rather specialized piece of machinery having a set of wheels, a set of arms for mating with a shipping pallet, and a lifting mechanism for lifting the arms. An operator positions the pallet jack with the arms lowered and inserted into a shipping pallet. The arms are raised, which raises the shipping pallet and the material carried on the shipping pallet. The pallet jack is then moved to another location using the wheels. The arms are then lowered, the shipping pallet is placed on the floor, and the pallet jack is then removed from the shipping pallet. Often pallet jacks are hydraulically or pneumatically operated so as to enable one person to move a great deal of material, sometimes thousands of pounds at a time, with little effort or risk of injury. 
     One of the relatively few drawbacks of pallet jacks is that a pallet jack can easily weigh several hundred pounds. This makes them rather difficult to move from one (1) location to a remote location. This is a particular problem when one (1) pallet jack must be frequently moved. If the pallet jack is not at the correctly location the delivery personnel who relied on it may have to move delivered goods one (1) piece at a time. Often a difficult, time consuming, and dangerous task. 
     In view of the foregoing there exists a need for a lightweight, easily transportable pallet jack. Beneficially such a pallet jack would be strong enough to move a great deal of weight while remaining easy to relocate. Preferably such a pallet jack would be made of aluminum for strength and lightweight. Ideally such a strong, lightweight pallet jack would eliminate the need for a pallet jack at the receiving location since delivery workers could simply bring their own. To that end such a pallet jack would ideally have foldable skid arms that can adjust to varying widths to fit pallets of different sizes. Beneficially the skid arms of such a pallet jack would fold up out of the way and would remain upright and out of the way when being moved. 
     SUMMARY OF THE INVENTION 
     The principles of the present invention provide for lightweight and easy to transport pallet jacks. Such pallet jacks can be configured to be sufficiently strong to move a lot of weight while remaining easy to move. Preferably the inventive pallet jacks are comprised of aluminum, have skid arms that are width-wise adjustable and that fold and remain upright. 
     A pallet jack that is in accord with the present invention includes a base platform and a base frame that extends over the base platform and further extends below the base platform. A pump assembly is mounted between the base frame and the base platform such that the pump assembly can raise and lower the base frame. The base platform is attached to a rear wheel assembly by a swivel connection. A support plate is attached to and extends away from the bottom of the base frame. The support plate includes a generally vertical, flat front having an upper edge. 
     The inventive pallet jack further includes a first fork bracket and a second fork bracket that extend from the support plate. A first fork prong is attached to the first fork bracket by a first hinge while a second fork prong is attached to the second fork bracket by a second hinge. A handle operates the pump assembly such that pumping the handle pushes the base frame upward. The first fork prong and the second fork prong vertically fold upright on the first and second hinges. 
     In practice the handle may pivotally connect to the pump assembly and it may include a valve control handle that can release pressure in the pump assembly to lower the base frame. A grip may be placed around the valve control handle. 
     Beneficially, the first fork bracket and the second fork bracket have inverted “U”-shaped front ends that attach to the support plate. The support plate may then include a plurality of recessed bracket seats along the upper edge for receiving the first and second fork brackets. The width between the first and second fork prongs can then be adjusted by locating the first and second fork brackets into different bracket seats. 
     It is beneficial that at least the first fork prong have a rear fork roller near the first hinge such that the rear fork roller can pivot into contact with a floor when the first fork prong is vertical. A locking pin can then pass through the first fork prong and the first fork bracket to lock the first fork prong when it is horizontal. A protective cover may be placed over the flat front and the upper edge, and a fastener can pass through the first fork bracket to lock the first fork bracket into a bracket seat. In addition, at least the first fork prong may include a front fork roller. 
     To assist keeping the fork prongs vertical a hinged support post may be attached to the base frame such that the support post can pivot vertically. Then, a securing member can be used to entrap the vertical support post and fork prongs. 
     An inventive pallet jack includes a base platform and a base frame that extends over the base platform and further extends below the base platform. A pump assembly is mounted between the base frame and the base platform such that the pump assembly can raise and lower the base frame. The base platform is attached to a rear wheel assembly by a swivel connection. A support plate is attached to and extends away from the bottom of the base frame. The support plate includes a generally vertical, flat front having an upper edge configured with at least three (3) bracket seats. 
     A first fork bracket extends from a first bracket seat while a second fork bracket extends from a second bracket seat. A first fork prong attaches to the first fork bracket and a second fork prong attaches to the second fork bracket. The inventive pallet jack further includes a handle for operating the pump assembly such that pumping the handle pushes the base frame upward. The separation between the first fork prong and the second fork prong depends on the first bracket seat and on the second bracket seat. 
     In practice the handle may include a valve control handle that is in fluid communication with the pump assembly such that the valve control handle can release pressure to lower the base frame. The handle may further include a grip around the valve control handle. 
     Preferably the first fork prong is attached to the first fork bracket by a first hinge and the second fork prong is attached to the second fork bracket by a second hinge. The first fork prong and the second fork prong can respectively fold vertically upright on the first and second hinges. In practice at least the first fork prong may include a rear fork roller that is adjacent to the first hinge such that the rear fork roller pivots into contact with a floor when the first fork prong is vertical. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The advantages and features of the present invention will become better understood with reference to the following more detailed description and claims taken in conjunction with the accompanying drawings, in which like elements are identified with like symbols, and in which: 
         FIG. 1  is a front perspective view of a foldable and width-adjustable pallet jack  10  that is in accord with a preferred embodiment of the present invention; 
         FIG. 2  is a side view of the foldable and width-adjustable pallet jack  10  shown in  FIG. 1 ; 
         FIG. 3  is a front perspective view of the foldable and width-adjustable pallet jack  10  shown in  FIGS. 1 and 2 , but depicted with a cover  48  removed to show a width-adjustment mechanism; 
         FIG. 4  is a fragmentary perspective view of the width-adjustment mechanism shown in  FIG. 3 ; 
         FIG. 5  is a front perspective view of the foldable and width-adjustable pallet jack  10  shown in  FIGS. 1 and 2 , but depicted with both fork prongs  20  raised; and, 
         FIG. 6  is a section view of a fork prong  20  of the foldable and width-adjustable pallet jack  10  taken along section line A-A of  FIG. 4 . 
       DESCRIPTIVE KEY 
       
           
           
             
                 10  foldable and width-adjustable pallet jack 
                 20  fork prong 
                 22  base frame 
                 23  support post recess 
                 24  base platform 
                 26  rear wheel 
                 28  pump assembly 
                 30  handle 
                 32  grip 
                 34  valve control handle 
                 36  support plate 
                 38  bracket seat 
                 40  fork bracket 
                 42  threaded aperture 
                 44  fastener aperture 
                 46  threaded fastener 
                 48  cover 
                 50  slot 
                 52  hinged connection 
                 53  hinge pin 
                 54  fork recess 
                 55  locking pin 
                 56  support post 
                 57  support post hinge 
                 58  securing member 
                 60  front fork roller 
                 61  pocket 
                 62  rear fork roller 
                 70  first push rod 
                 71  second push rod 
                 72  lever arm 
                 74  pivot pin 
                 75  roller opening 
                 76  clevis 
             
           
         
      
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The best mode for carrying out the invention is presented in terms of its preferred embodiment, herein depicted within  FIGS. 1 through 6 . However, the invention is not limited to the described embodiment and a person skilled in the art will appreciate that many other embodiments of the invention are possible without deviating from the basic concept of the invention, and that any such work around will also fall under scope of this invention. It is envisioned that other styles and configurations of the present invention can be easily incorporated into the teachings of the present invention, and only one particular configuration shall be shown and described for purposes of clarity and disclosure and not by way of limitation of scope. 
     The terms “a” and “an” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced items. 
     The present invention will be disclosure with reference to a certain embodiment which is illustrated in the accompanying drawings. Those figures depict a foldable and width-adjustable pallet jack, hereinafter described as a foldable pallet jack  10 . 
     Referring to  FIGS. 1 and 2 , the foldable pallet jack  10  is intended for engaging, lifting, and transporting a load such as a loaded shipping pallet. The foldable pallet jack  10  has two (2) fork prongs  20  that are laterally movable relative to one (1) another along a base frame  22 . This provides an adjustable fork prong width. The fork prongs  20  are configured to be insertable into a conventional shipping pallet. Finally, the fork prongs  20  are selectively foldable to remain upright. 
     The base frame  22  is configured to be height-adjustable via a hydraulic pump assembly  28 . The pump assembly  28  is operated by “pumping” an elongated handle  30  up and down relative to a base platform  24 . As is described in more detail subsequently this lifts and lowers the fork prongs  20  and any load attached thereto. The foldable pallet jack  10  includes at least one (1) rotatably rear wheel assembly  26  that is connected below the base platform  24  via a swivel connection  25 . The pump assembly  28  is mounted on the base platform  24 . As is typical with such pumps the pump assembly  28  includes a hydraulic jack having an internal piston (not shown) which is selectively pumped up and released down by the handle  30 . The handle  30  is beneficially pivotally connected to the pump assembly  28 . 
     The top of the pump assembly  28  is affixed to the bottom rear of the base frame  22 . Since the pump assembly  28  is on the base platform  24 , as the handle  30  is pumped the pump assembly  28  pushes the base frame  22  up. Turning now to  FIG. 6 , the pump assembly  28  also pushes on a first pushrod  70 . As is described in more detail subsequently, pushing on the first push rod  70  causes a front fork roller  60  to pivot to lift the front of the fork prongs  20  off the floor. Consequently, pumping the handle  30  causes the pump assembly  28  to synchronously lift both the base frame  22  and the fork prongs  20 . 
     The top of the handle  30  includes a grip  32  that surrounds a valve control handle  34 . As is typical for pallet jacks the valve control handle  34  selectively actuates a valve (not shown for clarity) that is in fluid communication with the pump assembly  28 . In the foldable pallet jack  10  moving the valve control handle  34  releases the pressure in the pump assembly  28 , which lowers the base frame  22  and the fork prongs  20 . 
     Refer now to  FIGS. 1 ,  3 , and  4 , which present various views of the foldable pallet jack  10 . The spatial positions of the fork prongs  20  are width adjustable. To that end the foldable pallet jack  10  has a width adjustment mechanism that includes a support plate  36  that is affixed to the lower front end of the base frame  22 . The width adjustment mechanism also includes a fork bracket  40  to which the proximal end of each fork prong  20  attach. The support plate  36  extends away from the base frame  22  to a generally vertical, flat front surface having an upper edge that is disposed away from the base frame  22 . 
     The support plate  36  is configured such that its upper edge forms a plurality of recessed bracket seats  38  for receiving the fork brackets  40 . To that end the support plate  36  forms a width-wise channel with the base frame  22 . The bracket seats  38  establish a set of selectable seat positions, and thus selectable fork prongs  20  widths. Typically, the bracket seats  38  are spaced twenty inches (20 in.) or twenty-seven inches (27 in.) apart. 
     Each of the fork brackets  40  includes an inverted “U”-shaped front end that is configured to ride along the support plate  36 . When a fork bracket  40  is positioned in a bracket seat  38  the “U”-shaped upper end of the fork bracket  40  fits within a bracket seat  38  such that the vertical portions of the fork bracket  40  rests upon and are supported by the vertical surfaces of the support plate  36  while the top of the inverted “U”-shaped rests on the upper edge of the support plate  36 . 
     As best shown in  FIGS. 4 and 6 , each bracket seat  38  includes a vertically disposed threaded aperture  42 . That aperture  42  receives a threaded fastener  46  that passes through a vertical fastener aperture  44  in the fork bracket  40 . The threaded fastener  46  is preferably a knob-stud device or a similar equivalent that enables a user to tighten the threaded fastener  46  without tools. Tightening the threaded fastener  46  secures the fork bracket  40  within the bracket seat  38 . Consequently, the fork prongs  20  are securely attached to the base frame  22 . 
     As best shown in  FIG. 5 , the foldable pallet jack  10  also includes an attachable cover  48  that covers and protects the width adjusting mechanism as well as the front of the base frame  20 . As shown, the cover  48  includes an elongated slot  50  that allows the fastener  46  to move laterally with the lateral movement of the fork bracket  40 . It is envisioned that the fastener  46  may include an integral washer feature or other stop feature which prevents its complete removal from the fork bracket  40 . 
     Referring now primarily to  FIGS. 4 ,  5 , and  6 , the fork prongs  20  are foldable with respect to the base frame  22 . To that end the proximal end of each fork bracket  40  extends horizontally outward short distances to an associated hinge  52 . Each hinge  52  includes a hinge pin  53  which extends laterally through an upper part of an associated fork prong  20  and an upper part of each fork bracket  40  (best shown in  FIG. 6 ). The hinge pin  53  allows its associated fork prong  20  to pivot upward to a generally vertical position. 
     The hinge  52  is suitably strong and durable to adequately bear a load such as a fully loaded pallet. To assist the hinge  52  the foldable pallet jack  10  further includes a locking pin  55  that adds stability when the fork prong  20  is horizontal. The locking pin  55  is located below and parallel with the hinge pin  53 . When the fork prong  20  is horizontal the locking pin  55  passes through lower apertures through the fork prong  20  and fork bracket  40 . Thus when the fork prong  20  is horizontal both the locking pin  55  and the hinge pin  53  support the load. However, the locking pin  55  is removable. When the locking pin  55  is removed the fork prong  20  can pivot upward as previously noted. When the locking pin  55  is in place a secondary locking element, such as a hair-pin cotter, a spring plunger, or the like may be used to retain the locking pin  55  in position. 
     Turning now primarily to  FIGS. 5 and 6 , each fork prong  20  includes a rear fork roller  62  at its proximal end. When the fork prong  20  is horizontal the rear fork rollers  62  fold into an associated fork bracket pocket  61 . This prevents the rear fork rollers  62  from interfering when the fork prongs  20  are under a load. When the fork prongs  20  are raised to a vertical position the rear fork rollers  62  pivot about the hinge pin  53  and extend out of the pocket  61  and into contact with the floor. This supports and stabilizes the front of the foldable pallet jack  10  and allows the foldable pallet jack  10  to be easily rolled. 
     Referring now to FIGS.  1  and  4 - 5  as required, the cover  48  includes a pair of fork recesses  54  that are disposed along its front. The fork recesses  54  align with the narrowest pair of bracket seats  38  and are sized to receive the proximal ends of the fork prong  20  when the fork prongs  20  are vertically raised. The top part of the base frame  22  includes a support post  56  on a support post hinge  57 . The support post  56  is a pivoting, extending appendage. When raised vertically the support post  56  enables attachment of an elongated securing member  58  which is wrapped around both fork prongs  20  and the support post  56 . This holds the fork prongs  20  vertically. The securing member  58  can be any suitably durable and flexible cord, cable, chain, or bungee cord. As best illustrated in  FIG. 1 , when not being used to vertically retain the fork prongs  20  the support post  56  are folded down to allow it to nest within a support post recess  23  that is molded into the base frame  22 . 
     As best shown in  FIGS. 2 and 6  each fork prong  20  includes the front fork roller  60  and the rear fork roller  62 . The front fork roller  60  attaches to the fork prong  20  using a lever arm  72  and a pivot pin  74 . The lever arm  72  and pivot pin  74  can cause the front fork roller  60  to move vertically, which causes the fork prongs  20  to rise upward to assist moving a load. Referring now to  FIG. 1 , each fork prong  20  includes a distally located roller opening  75  for receiving the front fork rollers  60  when the fork prongs  20  are lowered. 
     The front fork roller  60  can be moved down by the first pushrod  70  and by second pushrod  71  to lift the fork prongs  20 . As previously noted the first pushrod  70  is acted on by the pump assembly  28 . The first pushrod  70  travels within a bottom portion of the fork bracket  40 . As the first pushrod  70  is moved its distal end contacts and moves the second pushrod  71 , which resides within the fork prong  20 . The first  70  and second  71  pushrods are configured to align along a common centerline when the fork prong  20  is horizontal. 
     The distal end of the second pushrod  71  ends in a clevis  76 . The clevis  76  attaches to the lever arm  72  by a pin  101 . Moving the first  70  and second  71  pushrods toward the end of the fork prong  20  pivots the lever arm  72  to force the front fork roller  60  down relative to the fork prong  20 , thus lifting the fork prong  20 . To lower the fork prongs  20  the first  70  and second  71  pushrods move away from the distal end of the fork prong  20 . This allows the front fork roller  60  to move up relative to the fork prong  20 . 
     The hinged  52  enables physical separation of the first  70  and second  71  pushrods when the fork prongs  20  are moved vertically. It should be understood that similar angular drive components such as a universal joint, a sliding coupling, or the like may be used with equal benefit, and as such should not be interpreted as a limiting factor of the foldable pallet jack  10 . 
     The materials required to produce the foldable pallet jack  10  are readily available and well known. The majority of the components of the invention are beneficially made of aluminum, either machined formed. Standard manufacturing processes such as casting, extruding, cutting, welding, and fastening may be performed. Using aluminum (or a similar strong and light-weight material) for the base frame  22 , the base platform  24 , the fork prongs  20 , the fork brackets  40 , and the support plate  36  reduces the weight of the foldable pallet jack  10  while still offering the rigidity and durability required to handle heavy loads. Some components such as the hydraulic pump assembly  28  may require construction from steel due to the high internal pressures involved. Other components such as the wheels, rollers, handle, release valve mechanism, fasteners, and the like, would best be procured from wholesalers and manufacturers that deal in goods of that nature. 
     The preferred embodiment of the present invention can be used by the common user in a simple and effortless manner with little or no training. Using the foldable pallet jack  10  can be achieved by performing a series of steps (given below). However it can be appreciated that the operational steps can be performed in alternative order and as such the following operational descriptions should not be viewed as a limiting factor. 
     During use the fork prongs  20  can be adjusted to one (1) of a plurality of selectable width-adjusted positions. The fastener  46  is loosened or disengaged such that the fork bracket  40  is free to move. Each fork prong  20  can then be moved relative to the base frame  22  along the support plate  36 . To do so the fork prong  20  is lifted slightly upwardly such that the fork bracket  40  is removed from its original bracket seat  38 . Once removed the fork prong  20  can be slid along the support plate  36  to an appropriate position. Once the fork prong  20  is at a selected bracket seat  38 , the fork bracket  40  falls into that bracket seat  38  and the fastener aperture  44  of the associated fork bracket  40  and the threaded fastener  46  of the associated bracket seat  38  are aligned for insertion and tightening of the fastener  46 . Then the foldable pallet jack  10  can be used to lift and transport loads such as pallets in a conventional manner. 
     During storage of the foldable pallet jack  10  the fork prongs  20  are folded into a vertical position, preferably by moving the fork prongs  20  inward to the narrowest width-adjustable position. Each fork prong  20  is then folded upward about its hinged connection  52  to a vertical state. When vertical the proximal end of each fork prong  20  is positioned within a fork recess  54  of the cover  48  and the securing member  58  is wrapped around the fork prongs  20  and a vertical support post  56 . 
     The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention and method of use to the precise forms disclosed. Obviously many modifications and variations are possible in light of the above teaching. The embodiment was chosen and described in order to best explain the principles of the invention and its practical application, and to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omissions or substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but is intended to cover the application or implementation without departing from the spirit or scope of the claims of the present invention.