Abstract:
An improved hand cart has an elevator and a power system for controllably moving the elevator between an at rest position adjacent the ground and an elevated position. The hand cart has a pair of wheels for moving the hand cart and any accompanying load along the ground.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The subject invention relates to hand carts for mechanically transporting articles. More particularly, the subject invention relates to an improved hand cart which is adapted to also elevate articles for purposes of loading articles onto or off of the handcart.  
         [0003]     2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98  
         [0004]     The hand cart or hand truck of this invention is similar to heretofore utilized hand trucks which were incorporated to move articles laterally across the ground. However, it was discovered that the hand carts were extensively used with items that weighed considerably more than an individual worker could conveniently and safely lift to a resting place that was higher in elevation. An example of such use of a hand cart is the transporting of an oxygen bottle, which sometimes weighs in excess of one hundred pounds, and then lifting the oxygen bottle from immediately adjacent ground elevation into the bed of a truck or ambulance.  
         [0005]     Accidents often happened during movement of the oxygen bottle to a higher elevation. Sometimes the operator would smash his fingers. Other times the oxygen bottle would be accidentally dropped which often resulted into injury to the operator, an adjacent item which was struck by the falling bottle, or damage to the bottle itself. Other accidents during lifting of the excessively heavy bottles involved permanent injury to the operators lower back.  
         [0006]     Another example of such heavy weight objects that are customarily transported by hand carts and then necessarily loaded into the bed of a truck are heavy weight acetylene bottles that are used in welding.  
         [0007]     The present invention is directed to overcome one or more of the problems as set forth above.  
       BRIEF SUMMARY OF THE INVENTION  
       [0008]     In one aspect of the invention, a hand cart which has an “L” shaped frame connected to a pair of wheels and including a base and an upright member extending upwardly from the base, is improved by connecting an elevator to the hand cart frame. The elevator has a base and an upright element extending upwardly from the base. The elevator is slidably connected to the hand cart and a lifting system is connected to the elevator and the hand cart frame and adapted to controllably move the elevator to preselected elevations.  
     
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)  
       [0009]      FIG. 1  is a side view of the improved hand cart of this invention;  
         [0010]      FIG. 2  is a sectional view taken along line II-II of  FIG. 1  with portions of the cart removed;  
         [0011]      FIG. 3  is a diagrammatic view of one lifting system of this invention;  
         [0012]      FIG. 4  is a diagrammatic side view of the improved hand cart of this invention which has a hydraulically actuated lifting system; and  
         [0013]      FIG. 5  is a rear view of a portion of the improved hand cart of this invention showing the position of the wheels on the hand cart.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0014]     Referring to  FIG. 1 , the improved hand truck or cart  10  of this invention has a frame  12 , and elevator  14 , means  16  for slidably connecting the elevator  14  to the cart frame  12  and a lifting system  18  connected to the cart frame  12  and the elevator  14 . The cart frame  12  has a cart base  20 , a cart upright  22 , and a pair of wheels  24 ,  26  connected to the upwardly extending cart upright  22  at a location at which the wheels  24 , 26  are spaced from the ground in the upright position of the cart  10 . The elevator  14  has a base  28  and an upright element  30  connected to and extending upwardly from the base  28 .  
         [0015]     A lifting system  32  is connected to the elevator  14  and the cart frame  12  and is adapted to controllably move the elevator  14  between an at rest position, shown by solid lines, at which the cart base  20  and the elevator base  28  are in contact one with the other and an elevated position, shown by broken lines, at which the elevator base  28  is at a higher elevation than the cart base  20 .  
         [0016]     The lifting system  32  of  FIG. 1  has a flexible member  34 , such as a chain  36  as shown in  FIG. 3  or a rope or cable  38  as better seen in  FIGS. 1 and 2 . One end of the flexible member  34  is connected to the elevator  14 , the flexible member  34  passes over a pulley  35  which is attached to the cart upright  22  and the other end is connected to a power means  33  of the lifting system  32  which is connected to the cart upright  22 . Another embodiment of the lifting system  32  is shown in  FIG. 4  wherein the power means  33  for moving the elevator  14  is a fluid cylinder  40  which has a first end connected to the cart frame  12  and a second end connected to the elevator  14 . The fluid of the fluid cylinder can be air or a liquid such as hydraulic oil.  
         [0017]     The cart frame upright  22  has one of a guide rail  42  and a rail retainer  44  connected thereto and the elevator upright element  30  has the other of said guide rail  42  and rail retainer  44  connected thereto. In the preferred embodiment shown in  FIGS. 1 and 2 , there are two spaced apart guide rails  42 ,  43 . These guide rails  42 ,  43  are of a general “T” cross sectional configuration. The rail retainers  44 ,  45  extend about a portion of the associated guide rails  42 ,  43 . The rails  42 ,  43  and rail retainers  44 , 45  can be connected to their respective cart frame  12  or elevator upright element  30  by various means known in the art such as, for example, by welding.  
         [0018]     In the preferred embodiment of the lifting system  18  as shown in  FIG. 3 , a geared ratchet  46  is utilized which is adapted to require mechanical motion by an operator to move the elevator  14  a preselected distance upwardly and a preselected distance downwardly. Such a lifting system  18  is well known in the art and often utilized in a mechanical car jack thereby preventing the object being moved from moving at an unsafe speed or falling.  
         [0019]     In the preferred embodiment of this invention, the lifting system  18  is adapted for moving the elevator  14 , via a battery operated electric motor, a vertical distance in the range of about zero inches to about six feet. Many of the locations at which oxygen bottles or other objects are required to be positioned are four or more feet above ground level. More preferably the lifting system  18  is adapted for moving the elevator  14  a vertical distance greater than about four feet which is sufficiently high to reach the bed of most trucks.  
         [0020]     Although  FIG. 2  shows the preferred embodiment of a pair of guide rails  42 , 43  and associated rail retainers  44 , 45 , it should be understood that the connecting means  16  can be only the flexible member  34  or can be of other construction. Examples of such other construction are outwardly extending stops positioned on opposed sides of the cart upright  22  in the pathway of the elevator upright element  30  maintaining against movement of the element sideways across the cart upright  22 . In another construction, grooves can be formed in either the cart upright  22  or the elevator upright element  30 , which grooves receive protrusions extending from the other of the uprights  22  or  30 . It should also be understood that connecting and maintaining means of other construction can be utilized without departing from this invention. Since it is often required to raise the heavy loads to a relatively high elevations, it is important that the cart  10  be stable at the elevated position of the elevator  14 . To provide such desired stability, one or more retaining straps  48 ,  49 , see  FIG. 4 , are connected to the elevator upright element  30  and adapted to encircle and maintain an object on the elevator  14 . Further, as shown in  FIGS. 1 and 5 , the wheels  24 ,  26  are connected to the elevator upright element  30  at a location sufficient for said wheels  24 ,  26  being at a higher elevation than the cart base  20  when the cart upright element  30  is in a general vertical position, as shown in  FIG. 1  and that each wheel  24 ,  26  be positioned on an opposed side of the cart base  20  at a location outwardly spaced from a respective side of the base  20  a distance of at least six inches. For further increasing stability it is preferred that the length of the cart base  20  is greater than the length of the elevator base  28  and that the cart upright  22  be oriented relative to the cart base  20  at an angle  50  less than ninety degrees.  
         [0021]     Other aspects, objects, and advantages can be obtained from a study of the drawings, the disclosure and the appended claims.