Hole digging tool

BACKGROUND OF THE INVENTION

Various specialized tools for digging holes and the like are known to gardeners and landscape workers. Often, when an application is small, it is more efficient to use a hand-operated tool rather than bringing in a large, power tool to the work site. This is particularly true when a small property owner wishes to install a fence wherein a limited number of post holes are needed. Rather than renting or buying a mechanical auger, a hand tool is often a more viable solution. However, hand tools currently used for post hole digging are frequently clumsy to use, unduly taxing on the user, and inefficient in operation. A tool exhibiting some of these shortcomings is the scissors-type digger wherein two shovel blades, affixed to respective handles, are aligned in a face-to-face orientation and pivotally connected to move clamshell style between open and closed positions. Use of a tool of this type requires the user to maintain the closed position as excess soil is removed from the hole being dug. This may lead to upper body fatigue as well as inefficient soil removal as user fatigue loosens the closed blades and soil falls back into the freshly dug hole. Further, it is difficult to maintain a uniform hole diameter as the hole is dug deeper. Auger type diggers create a more uniform hole diameter, but still create difficulties for soil removal and fatigue as the user is required to exert rotational movement along the handle length. By way of background, it is presently believed that the shovel pivot tool, manufactured and sold by the assignee of the present invention, and commercially known as the “Pit Boss” is the closest related art reference. This tool provides a solution to a number of the shortcomings present in the aforementioned devices, namely, increased fatigue, non-uniformity of hole diameter, and inefficient soil removal. This device includes a shovel-type blade pivotally attached to a main shaft or handle. The device also includes a lever arm hingedly attached to the shovel such that when the shovel and lever arm are positioned on the ground in digging position, the lever arm is parallel to the main handle shaft.

SUMMARY OF THE INVENTION

The present invention provides a solution to the problems associated with the devices mentioned above, namely user fatigue, lack of uniformity of hole size throughout its depth, and difficulty of use. The present invention further provides an improvement for a hole digging tool of the pivot type. The tool comprises a ground-penetrating portion, such as a shovel, pivotally attached to a conventional handle shaft. The shovel blade preferably includes two upturned portions and is further pivotally attached to an inverted, Y-shaped, movable shaft. The arms of the Y-shaped shaft each respectively pivotally attach to an upturned portion of the shovel, while the leg of the shaft runs parallel to and substantially coextensive with a portion of the handle shaft length. The improvement comprises the addition of a secondary lever mechanism and handle. This addition allows the user to gain added leverage over the shovel. Additionally, the user gains an additional lift surface when lifting the material-laden shovel from a hole. Furthermore, the present invention provides an improved primary lever mechanism, whereby movement of the main lever handle causes all linked components to move in parallel, causing the moving ratio to be 1:1.

DESCRIPTION OF THE DRAWINGS

FIG. 1

is a perspective view of the hole digging tool of the present invention.

FIG. 2

is an exploded view of the hole digging tool of FIG.

1

.

FIG. 3

a

is a side elevational view of the hole digging tool and showing the lever handles and shovel in generally parallel alignment with the handle shaft, in position ready to commence digging.

FIG. 3

b

is a side elevational view of the hole digging tool and showing the lever handles and shovel in an intermediate position.

FIG. 3

c

is a side elevational view of the hole digging tool and showing the lever handles and shovel in perpendicular relation to the handle shaft, in position to move matter from one level to another.

DETAILED DESCRIPTION

Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention which may be embodied in other specific structure. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.

The preferred embodiment of the improved hole digging tool, indicated generally by the reference numeral

10

, may be seen in the views of

FIGS. 1-3

c

, inclusive. In the preferred embodiment, the hole digging tool

10

includes an elongated shaft or primary handle member

12

, having a distal end

14

and a working end

16

, and a digging member

18

(seen as a shovel in these views). The handle may be fabricated from wood, or may be made from any other substance such as fiberglass-filled resin, or other known materials having sufficient strength for digging and lifting. The digging member

18

is pivotally attached to the working end

16

of the primary handle member

12

by way of a movable hinge member

20

. The hinge member

20

may further include an upstanding backplate

22

which is secured to the handle member

12

by way of conventional bolts

24

. The backplate

22

provides added stability and strength to the hinge member

20

and assists the shovel

18

in retaining dirt or debris

56

while lifting out of a hole (not shown). The improved digging tool

10

is further provided with a secondary, movable shaft

26

. The secondary, movable shaft

26

is Y-shaped and includes two arm portions

28

and an elongated leg portion

30

. Each arm portion

28

is pivotally connected to the digging member

14

at respective pivotal points

29

a

,

29

b

by way of conventional attachment means such as bolts or screws

24

. The digging member (i.e. shovel

18

), back plate

22

, and secondary shaft

26

may be forged or stamped from sheet steel or the like. As seen in

FIGS. 1 and 2

, the digging member

18

may be provided with two upturned portions

32

, having apertures

30

a

(shown in

FIG. 2

) to provide an attachment surface for the arm portions

30

of the secondary shaft

26

, and to further allow the digging member

18

to carry debris

56

, such as soil (shown in phantom) out of the digging area. A primary lever mechanism

34

, including two oppositely disposed lever arms

36

, is pivotally attached to the handle member

12

at a pivot point

35

, intermediate the ends

14

,

16

. The primary lever mechanism

34

further includes a handle portion

38

extending from and secured to one of the oppositely disposed lever arms

36

. Handle portion

38

may include radially spaced, longitudinal grooves

58

to provide additional gripping elements. The other of the oppositely disposed lever arms is pivotally secured to the distal end

40

of the elongated leg portion

30

of the secondary, movable shaft

26

, such that as the handle portion

38

rotates clockwise upwardly relative to

FIG. 1

, and relative to the primary handle

12

, the distal end

40

of the secondary shaft

26

, moves downward relative to the primary handle

12

.

The improved hole digging tool

10

is further provided with a secondary lever mechanism

42

. The secondary lever mechanism

42

includes an integrally formed handle portion

44

and an angled lever arm

46

. The secondary lever mechanism

42

is pivotally attached to the primary handle

12

at pivot point

48

and the secondary shaft

26

at pivot point

50

, at a predetermined placement intermediate the digging member

18

and the primary lever mechanism

34

. In the preferred embodiment of the present invention, the secondary lever mechanism

42

is arranged to be located at any of a plurality of predetermined locations

48

,

52

located along the primary handle

12

and secondary shaft

26

. This allows the user to secure the secondary lever mechanism

42

at a location suitable for the hole to be dug. For example, if the hole desired is to be rather deep, the user may place the secondary lever

42

at a point closer to the distal end

14

of the primary handle

12

. This way, the user may insert the tool

10

into a deep hole while continuing to access the handle portion

44

of the secondary lever

42

. The secondary lever

42

and handle portion

44

afford the user additional leverage while moving the soil to be removed, while the handle portion

44

further aids the user by supplying an additional lift surface when removing the debris-laden tool

10

from a hole. To allow the flexibility of multiple attachment points, both the primary handle

12

and secondary shaft

26

are provided with a plurality of attachment points, seen as screw-receiving holes

52

. As shown in the Figures, the secondary lever mechanism

42

is preferably releasably attached to the primary handle

12

and secondary movable shaft

26

by way of conventional threaded bolts

54

.

Seen particularly in

FIG. 3

a

, is the improved hole digging tool

10

in an initial operating position. The primary lever mechanism

34

and secondary lever mechanism

42

with their handles

38

and

44

are in parallel relationship with the primary handle

12

. The digging member

18

is extended and ready for use.

With reference to

FIG. 3

b

, the tool

10

is shown at an intermediate step in the digging process. Here, the lever mechanisms

34

and

42

with digging member

18

, are shown partially rotated around their respective pivot points,

29

a

,

29

b

,

35

,

48

, and

50

and wherein the lever handles

38

,

44

are rotated counter-clockwise relative to

FIG. 3

b

and in the direction of the arrows.

FIG. 3

b

particularly shows the tool

10

prior to being lifted out of a hole in process (not shown) but after a load of dirt or other matter to be removed has been loosened.

FIG. 3

c

illustrates the improved tool

10

in its lifting position. Here, the lever mechanisms

34

and

42

are rotated to a position perpendicular to the primary handle

12

. The digging member

18

is also rotated to a position substantially perpendicular to the primary handle

12

, such that as the tool is lifted from the hole-in-process, the debris

56

to be carried out rests on the rotated digging member

18

.

The foregoing is considered as illustrative only of the principles of the invention. Furthermore, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.