Abstract:
Portable motorized hoe comprises a narrow elongate casing ( 1 ) forming the machine frame and comprising two complementary half-casings ( 2, 3 ) connected together in a direction parallel to the axis ( 99 ) of rotation of a hoeing unit, to provide, with reference to the working position assumed by the operator, in the part closest thereto a machine transporting and manoeuvring handle, in the intermediate part a housing containing an electric motor ( 80 ), and in the part farthest therefrom the support seats for said hoeing unit, the shaft of which is linkage-connected to said electric motor.

Description:
FIELD OF THE INVENTION 
     This invention relates to a portable motorized hoe, used typically in a domestic environment for cultivating gardens, flowerbeds, vegetable gardens and the like. 
     SUMMARY OF THE INVENTION 
     An object of the invention is to provide a compact and lightweight motorized hoe which is easily maneuvered and transported. 
     A further object is to provide a portable motorized hoe in which all the moving parts, excluding the active region of the hoeing wheels, are protected or masked, and in which the outer machine structure does not comprise projecting elements or undersurface elements which could catch on objects, such as branches or the like. 
     These and other objects are attained by the present invention, which affords a device that is simple, rational and reliable in construction, inexpensive and safe to use. 
     Specifically, the motorized hoe of the invention comprises a narrow, elongated casing forming both the frame for the machine and the member by which it is maneuvered and transported. 
     The casing comprises two complementary half-casings connected together in a direction parallel to the axis of rotation of a hoeing unit With reference to the working position assumed by the operator, in the part closest thereto, a machine transporting and maneuvering handle is provided. In the intermediate part, a housing containing an electric motor is provided, and in the part farthest therefrom, support seats for the hoeing unit are provided, whereby the shaft is linkage-connected to the electric motor. 
     Preferably, the two half-casings each consist of two portions having substantially the same length and removably connected together. 
     In the intermediate part of the casing, there is also preferably provided a housing accessible from the outside for containing a storage battery for powering the electric motor. 
     The linkage connection between the electric motor and the hoeing unit is in the form of a step-down gear train. 
     Finally, the support seats for the hoeing unit are located in proximity to the plane in which the two half-casings are connected together, and rotatably carry the shaft of the downstream gearwheel of the gear train. 
     The opposite ends of the shaft extend beyond two flanges and each carries at least two hoeing rotors which are upperly enclosed by a terminal arched transverse wall of the respective half-casing to form a barrier which provides protection against stones and the like. 
     The construction and merits of the invention will be more apparent from the ensuing detailed description given with reference to the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the assembled invention; and 
     FIG. 2 is an exploded perspective view thereof on a smaller scale. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     From the figures it can be seen that the motorized hoe comprises a narrow, elongated casing indicated overall by the reference numeral  1  and, as will be apparent hereinafter, forms both the frame of the machine and the member by which it is maneuvered and transported. 
     The casing  1  is of upwardly narrowing, tapered form which, in side view, is arched, with its concavity facing the side on which the operator is located during the use of the machine, i.e., upwards towards the right with reference to FIG.  1 . 
     The casing  1  consists of two complementary half-casings, the right of which is indicated by  2  and the left by  3 . The half-casings are connected together in the direction defined by the axis of rotation  99  (see FIG. 1) of the hoeing unit described hereinafter. 
     With reference to FIG. 2, each half-casing comprises two portions  20 ,  21  and  30 ,  31 , respectively, of which portions  20 ,  30  are situated in proximity to the operator and form the handle for transporting and maneuvering the machine, while portions  21 ,  31  are more distant from the operator and form a hollow container for masking and containing the moving members of the machine, with the exception of the lower active region of the hoeing unit. The two half-casings  2 ,  3  are connected together by a series of self-tapping screws (not shown) to be inserted through respective holes  22  provided in the half-casing  2  and screwed into corresponding hollow bosses  32  branching from the inner surface of the half-casing  3 . 
     The lower end of the handle  20 ,  30  has a cylindrical constriction  33  which mates with an inner matching seat provided at the top of the hollow container  21 ,  31 , the handle  20 ,  30  and the hollow container  21 ,  31  being made rigid by at least one of the screws which passes through aligned holes  34 ,  35  provided in the portion  21  and in the right side of the constriction  33 , respectively, and is screwed into a hollow inner boss  36  branching from the left side of said constriction  33 . 
     A U-shaped handgrip  5  is removably fixed by two threaded plugs  4  (of which only one is visible in FIG. 2) to one side of the top of the handle  20 ,  30 , the handle top also having a seat  6  for mounting a switch (not shown). 
     As can be seen in FIG. 2, the lower part of the hollow container  21 ,  31  comprises an upper housing  7  for containing a storage battery  70 , and a lower compartment  8  for containing an electric motor  80  and a step-down gear unit. 
     The housing  7  is accessible from the outside via a removable front cover  9 , said compartment  8  being closed for connecting together the two half-casings  2  and  3 . 
     It should be noted that the motor  80  is electrically connected to a 12V storage battery  70  via said switch, and the wires for the connection are housed inside the machine casing. 
     Instead of incorporating a storage battery  70 , the motor  80  can be connected to a usual 220V current socket via an electric cable extending from the upper end of the handle  20 ,  30  and a current rectifier. 
     Alternatively, an equivalent alternating current motor can be used. The casing of the motor  80  is fixed by screws to the top of the right side of the compartment  8  via a window indicated by  10  in FIG.  2  and provided with a snap-closure cover  11  (see FIG.  1 ). On the opposite side of the compartment  8 , there is a holed plate  17  acting as a support for the exit shaft of the motor  80 , and a pinion being keyed on said exit shaft (not visible in the figure). The pinion engages the greater-diameter gear  55  of a double ring gear, the lesser-diameter gear  66  of which engages an intermediate gear  44  which, in turn, engages a motion exit or terminal gear  77 . 
     As can be seen from FIG. 2, the double ring gear  55 ,  66  and the intermediate gear  44  are contained in the compartment  8 , the sides of which are provided with suitable means (such as that indicated by  88 ) for supporting the gears and their bearings (such as those indicated by  12 ), whereas the terminal gear  77  lies between two holed flanges  13  positioned in proximity to the connection surfaces of the half-casings  2  and  3 . 
     The terminal gear  77  is keyed onto a hollow shaft  14 , the two opposing portions of which form axle shafts of the hoeing unit. 
     Specifically, each axle shaft comprises a smooth portion close to the gear  77 , followed by a threaded portion, the former acting as the seat for the inner race of a respective ball bearing  15 , and the latter passing beyond a bushing  16  on the flange  13  which acts as the seat for the outer ring of the bearing  15 . 
     On the projecting portion of each axle shaft, there are provided, starting from the respective bushing  16 : a ring  18  screwed onto the axle shaft and having an undercut to receive the face bushing portion in order to protect the bearing  15 ; a first hoeing rotor  19  comprising six radial arms bent alternately in one direction and the other; a spacer  192  provided at its opposing ends with two hexagonal projections to engage in respective hexagonal holes  201  provided in the center of said hoeing rotor  19  and in the center of an opposing hoeing rotor  191 ; and an end ring  193 . 
     The entire assembly is clamped together by a single threaded through rod  300  which, at one end, has a head received in a recess in one of said rings  193  and, at the other end, is provided with a washer  301  and a locking nut  302  received in a recess in the opposite ring  193 . Finally, it should be noted that the upper part of the cylindrical surface swept by the hoeing rotors  19  and  191  is overlaid by an arched wall which forms the base of the compartment  8  and extends beyond the transverse outline of the casing to form a protection barrier against stones. 
     By way of example, the following are significant data of the aforedescribed portable motorized hoe B: 
     
       
         
               
               
             
           
               
                   
               
             
             
               
                 speed of motor 80: 
                 16800 r.p.m. (if 12 V) 
               
               
                   
                 23500 r.p.m. (if 220 V) 
               
               
                 power of motor 80: 
                 172 W (if 12 V) 
               
               
                   
                 156 W (if 220 V) 
               
               
                 capacity of storage battery 70: 
                 7 Ah 
               
               
                 rotational speed of hoeing rotors 19, 191: 
                 200 r.p.m. (if 12 V) 
               
               
                   
                 220 r.p.m. (if 220 V) 
               
               
                 diameter of hoeing rotors: 
                 160 mm 
               
               
                 width of worked strip: 
                 160 mm. 
               
               
                   
               
             
          
         
       
     
     The merits and advantages of the invention are apparent from the foregoing and from an examination of the accompanying figures.